BigDecimal
public
class
BigDecimal
extends Number
implements
Comparable<BigDecimal>
java.lang.Object | ||
↳ | java.lang.Number | |
↳ | java.math.BigDecimal |
Immutable, arbitrary-precision signed decimal numbers. A BigDecimal
consists of an arbitrary precision integer
unscaled value and a 32-bit
integer scale. If zero or positive,
the scale is the number of digits to the right of the decimal
point. If negative, the unscaled value of the number is multiplied
by ten to the power of the negation of the scale. The value of the
number represented by the BigDecimal
is therefore
(unscaledValue × 10-scale)
.
The BigDecimal
class provides operations for
arithmetic, scale manipulation, rounding, comparison, hashing, and
format conversion. The toString()
method provides a
canonical representation of a BigDecimal
.
The BigDecimal
class gives its user complete control
over rounding behavior. If no rounding mode is specified and the
exact result cannot be represented, an ArithmeticException
is thrown; otherwise, calculations can be carried out to a chosen
precision and rounding mode by supplying an appropriate MathContext
object to the operation. In either case, eight
rounding modes are provided for the control of rounding.
Using the integer fields in this class (such as ROUND_HALF_UP
) to represent rounding mode is deprecated; the
enumeration values of the RoundingMode
enum
, (such
as RoundingMode#HALF_UP
) should be used instead.
When a MathContext
object is supplied with a precision
setting of 0 (for example, MathContext#UNLIMITED
),
arithmetic operations are exact, as are the arithmetic methods
which take no MathContext
object. As a corollary of
computing the exact result, the rounding mode setting of a MathContext
object with a precision setting of 0 is not used and
thus irrelevant. In the case of divide, the exact quotient could
have an infinitely long decimal expansion; for example, 1 divided
by 3. If the quotient has a nonterminating decimal expansion and
the operation is specified to return an exact result, an ArithmeticException
is thrown. Otherwise, the exact result of the
division is returned, as done for other operations.
When the precision setting is not 0, the rules of BigDecimal
arithmetic are broadly compatible with selected modes
of operation of the arithmetic defined in ANSI X3.274-1996 and ANSI
X3.274-1996/AM 1-2000 (section 7.4). Unlike those standards,
BigDecimal
includes many rounding modes. Any conflicts
between these ANSI standards and the BigDecimal
specification are resolved in favor of BigDecimal
.
Since the same numerical value can have different
representations (with different scales), the rules of arithmetic
and rounding must specify both the numerical result and the scale
used in the result's representation.
The different representations of the same numerical value are
called members of the same cohort. The natural order of BigDecimal
considers members of the same cohort to be equal to each other. In
contrast, the equals
method requires both the
numerical value and representation to be the same for equality to
hold. The results of methods like scale()
and unscaledValue()
will differ for numerically equal values with
different representations.
In general the rounding modes and precision setting determine
how operations return results with a limited number of digits when
the exact result has more digits (perhaps infinitely many in the
case of division and square root) than the number of digits returned.
First, the total number of digits to return is specified by the
MathContext
's precision
setting; this determines
the result's precision. The digit count starts from the
leftmost nonzero digit of the exact result. The rounding mode
determines how any discarded trailing digits affect the returned
result.
For all arithmetic operators, the operation is carried out as though an exact intermediate result were first calculated and then rounded to the number of digits specified by the precision setting (if necessary), using the selected rounding mode. If the exact result is not returned, some digit positions of the exact result are discarded. When rounding increases the magnitude of the returned result, it is possible for a new digit position to be created by a carry propagating to a leading "9" digit. For example, rounding the value 999.9 to three digits rounding up would be numerically equal to one thousand, represented as 100×101. In such cases, the new "1" is the leading digit position of the returned result.
For methods and constructors with a MathContext
parameter, if the result is inexact but the rounding mode is UNNECESSARY
, an ArithmeticException
will be thrown.
Besides a logical exact result, each arithmetic operation has a preferred scale for representing a result. The preferred scale for each operation is listed in the table below.
Operation | Preferred Scale of Result |
---|---|
Add | max(addend.scale(), augend.scale()) |
Subtract | max(minuend.scale(), subtrahend.scale()) |
Multiply | multiplier.scale() + multiplicand.scale() |
Divide | dividend.scale() - divisor.scale() |
Square root | radicand.scale()/2 |
1/32
is 0.03125
.
Before rounding, the scale of the logical exact intermediate
result is the preferred scale for that operation. If the exact
numerical result cannot be represented in precision
digits, rounding selects the set of digits to return and the scale
of the result is reduced from the scale of the intermediate result
to the least scale which can represent the precision
digits actually returned. If the exact result can be represented
with at most precision
digits, the representation
of the result with the scale closest to the preferred scale is
returned. In particular, an exactly representable quotient may be
represented in fewer than precision
digits by removing
trailing zeros and decreasing the scale. For example, rounding to
three digits using the floor
rounding mode,
19/100 = 0.19 // integer=19, scale=2
but
21/110 = 0.190 // integer=190, scale=3
Note that for add, subtract, and multiply, the reduction in scale will equal the number of digit positions of the exact result which are discarded. If the rounding causes a carry propagation to create a new high-order digit position, an additional digit of the result is discarded than when no new digit position is created.
Other methods may have slightly different rounding semantics.
For example, the result of the pow
method using the
specified algorithm can
occasionally differ from the rounded mathematical result by more
than one unit in the last place, one ulp.
Two types of operations are provided for manipulating the scale
of a BigDecimal
: scaling/rounding operations and decimal
point motion operations. Scaling/rounding operations (setScale
and round
) return a
BigDecimal
whose value is approximately (or exactly) equal
to that of the operand, but whose scale or precision is the
specified value; that is, they increase or decrease the precision
of the stored number with minimal effect on its value. Decimal
point motion operations (movePointLeft
and
movePointRight
) return a
BigDecimal
created from the operand by moving the decimal
point a specified distance in the specified direction.
As a 32-bit integer, the set of values for the scale is large,
but bounded. If the scale of a result would exceed the range of a
32-bit integer, either by overflow or underflow, the operation may
throw an ArithmeticException
.
For the sake of brevity and clarity, pseudo-code is used
throughout the descriptions of BigDecimal
methods. The
pseudo-code expression (i + j)
is shorthand for "a
BigDecimal
whose value is that of the BigDecimal
i
added to that of the BigDecimal
j
." The pseudo-code expression (i == j)
is
shorthand for "true
if and only if the
BigDecimal
i
represents the same value as the
BigDecimal
j
." Other pseudo-code expressions
are interpreted similarly. Square brackets are used to represent
the particular BigInteger
and scale pair defining a
BigDecimal
value; for example [19, 2] is the
BigDecimal
numerically equal to 0.19 having a scale of 2.
All methods and constructors for this class throw
NullPointerException
when passed a null
object
reference for any input parameter.
Summary
Constants | |
---|---|
int |
ROUND_CEILING
This constant was deprecated
in API level 33.
Use |
int |
ROUND_DOWN
This constant was deprecated
in API level 33.
Use |
int |
ROUND_FLOOR
This constant was deprecated
in API level 33.
Use |
int |
ROUND_HALF_DOWN
This constant was deprecated
in API level 33.
Use |
int |
ROUND_HALF_EVEN
This constant was deprecated
in API level 33.
Use |
int |
ROUND_HALF_UP
This constant was deprecated
in API level 33.
Use |
int |
ROUND_UNNECESSARY
This constant was deprecated
in API level 33.
Use |
int |
ROUND_UP
This constant was deprecated
in API level 33.
Use |
Fields | |
---|---|
public
static
final
BigDecimal |
ONE
The value 1, with a scale of 0. |
public
static
final
BigDecimal |
TEN
The value 10, with a scale of 0. |
public
static
final
BigDecimal |
ZERO
The value 0, with a scale of 0. |
Public constructors | |
---|---|
BigDecimal(char[] in, int offset, int len)
Translates a character array representation of a
|
|
BigDecimal(char[] in, int offset, int len, MathContext mc)
Translates a character array representation of a
|
|
BigDecimal(char[] in)
Translates a character array representation of a
|
|
BigDecimal(char[] in, MathContext mc)
Translates a character array representation of a
|
|
BigDecimal(String val)
Translates the string representation of a |
|
BigDecimal(String val, MathContext mc)
Translates the string representation of a |
|
BigDecimal(double val)
Translates a |
|
BigDecimal(double val, MathContext mc)
Translates a |
|
BigDecimal(BigInteger val)
Translates a |
|
BigDecimal(BigInteger val, MathContext mc)
Translates a |
|
BigDecimal(BigInteger unscaledVal, int scale)
Translates a |
|
BigDecimal(BigInteger unscaledVal, int scale, MathContext mc)
Translates a |
|
BigDecimal(int val)
Translates an |
|
BigDecimal(int val, MathContext mc)
Translates an |
|
BigDecimal(long val)
Translates a |
|
BigDecimal(long val, MathContext mc)
Translates a |
Public methods | |
---|---|
BigDecimal
|
abs(MathContext mc)
Returns a |
BigDecimal
|
abs()
Returns a |
BigDecimal
|
add(BigDecimal augend)
Returns a |
BigDecimal
|
add(BigDecimal augend, MathContext mc)
Returns a |
byte
|
byteValueExact()
Converts this |
int
|
compareTo(BigDecimal val)
Compares this |
BigDecimal
|
divide(BigDecimal divisor, int scale, int roundingMode)
This method was deprecated
in API level 33.
The method |
BigDecimal
|
divide(BigDecimal divisor, int scale, RoundingMode roundingMode)
Returns a |
BigDecimal
|
divide(BigDecimal divisor, int roundingMode)
This method was deprecated
in API level 33.
The method |
BigDecimal
|
divide(BigDecimal divisor, MathContext mc)
Returns a |
BigDecimal
|
divide(BigDecimal divisor, RoundingMode roundingMode)
Returns a |
BigDecimal
|
divide(BigDecimal divisor)
Returns a |
BigDecimal[]
|
divideAndRemainder(BigDecimal divisor, MathContext mc)
Returns a two-element |
BigDecimal[]
|
divideAndRemainder(BigDecimal divisor)
Returns a two-element |
BigDecimal
|
divideToIntegralValue(BigDecimal divisor, MathContext mc)
Returns a |
BigDecimal
|
divideToIntegralValue(BigDecimal divisor)
Returns a |
double
|
doubleValue()
Converts this |
boolean
|
equals(Object x)
Compares this |
float
|
floatValue()
Converts this |
int
|
hashCode()
Returns the hash code for this |
int
|
intValue()
Converts this |
int
|
intValueExact()
Converts this |
long
|
longValue()
Converts this |
long
|
longValueExact()
Converts this |
BigDecimal
|
max(BigDecimal val)
Returns the maximum of this |
BigDecimal
|
min(BigDecimal val)
Returns the minimum of this |
BigDecimal
|
movePointLeft(int n)
Returns a |
BigDecimal
|
movePointRight(int n)
Returns a |
BigDecimal
|
multiply(BigDecimal multiplicand, MathContext mc)
Returns a |
BigDecimal
|
multiply(BigDecimal multiplicand)
Returns a |
BigDecimal
|
negate()
Returns a |
BigDecimal
|
negate(MathContext mc)
Returns a |
BigDecimal
|
plus()
Returns a |
BigDecimal
|
plus(MathContext mc)
Returns a |
BigDecimal
|
pow(int n, MathContext mc)
Returns a |
BigDecimal
|
pow(int n)
Returns a |
int
|
precision()
Returns the precision of this |
BigDecimal
|
remainder(BigDecimal divisor)
Returns a |
BigDecimal
|
remainder(BigDecimal divisor, MathContext mc)
Returns a |
BigDecimal
|
round(MathContext mc)
Returns a |
int
|
scale()
Returns the scale of this |
BigDecimal
|
scaleByPowerOfTen(int n)
Returns a BigDecimal whose numerical value is equal to
( |
BigDecimal
|
setScale(int newScale, int roundingMode)
This method was deprecated
in API level 33.
The method |
BigDecimal
|
setScale(int newScale)
Returns a |
BigDecimal
|
setScale(int newScale, RoundingMode roundingMode)
Returns a |
short
|
shortValueExact()
Converts this |
int
|
signum()
Returns the signum function of this |
BigDecimal
|
sqrt(MathContext mc)
Returns an approximation to the square root of |
BigDecimal
|
stripTrailingZeros()
Returns a |
BigDecimal
|
subtract(BigDecimal subtrahend)
Returns a |
BigDecimal
|
subtract(BigDecimal subtrahend, MathContext mc)
Returns a |
BigInteger
|
toBigInteger()
Converts this |
BigInteger
|
toBigIntegerExact()
Converts this |
String
|
toEngineeringString()
Returns a string representation of this |
String
|
toPlainString()
Returns a string representation of this |
String
|
toString()
Returns the string representation of this |
BigDecimal
|
ulp()
Returns the size of an ulp, a unit in the last place, of this
|
BigInteger
|
unscaledValue()
Returns a |
static
BigDecimal
|
valueOf(double val)
Translates a |
static
BigDecimal
|
valueOf(long val)
Translates a |
static
BigDecimal
|
valueOf(long unscaledVal, int scale)
Translates a |
Inherited methods | |
---|---|
Constants
ROUND_CEILING
public static final int ROUND_CEILING
This constant was deprecated
in API level 33.
Use RoundingMode#CEILING
instead.
Rounding mode to round towards positive infinity. If the
BigDecimal
is positive, behaves as for
ROUND_UP
; if negative, behaves as for
ROUND_DOWN
. Note that this rounding mode never
decreases the calculated value.
Constant Value: 2 (0x00000002)
ROUND_DOWN
public static final int ROUND_DOWN
This constant was deprecated
in API level 33.
Use RoundingMode#DOWN
instead.
Rounding mode to round towards zero. Never increments the digit prior to a discarded fraction (i.e., truncates). Note that this rounding mode never increases the magnitude of the calculated value.
Constant Value: 1 (0x00000001)
ROUND_FLOOR
public static final int ROUND_FLOOR
This constant was deprecated
in API level 33.
Use RoundingMode#FLOOR
instead.
Rounding mode to round towards negative infinity. If the
BigDecimal
is positive, behave as for
ROUND_DOWN
; if negative, behave as for
ROUND_UP
. Note that this rounding mode never
increases the calculated value.
Constant Value: 3 (0x00000003)
ROUND_HALF_DOWN
public static final int ROUND_HALF_DOWN
This constant was deprecated
in API level 33.
Use RoundingMode#HALF_DOWN
instead.
Rounding mode to round towards "nearest neighbor"
unless both neighbors are equidistant, in which case round
down. Behaves as for ROUND_UP
if the discarded
fraction is > 0.5; otherwise, behaves as for
ROUND_DOWN
.
Constant Value: 5 (0x00000005)
ROUND_HALF_EVEN
public static final int ROUND_HALF_EVEN
This constant was deprecated
in API level 33.
Use RoundingMode#HALF_EVEN
instead.
Rounding mode to round towards the "nearest neighbor"
unless both neighbors are equidistant, in which case, round
towards the even neighbor. Behaves as for
ROUND_HALF_UP
if the digit to the left of the
discarded fraction is odd; behaves as for
ROUND_HALF_DOWN
if it's even. Note that this is the
rounding mode that minimizes cumulative error when applied
repeatedly over a sequence of calculations.
Constant Value: 6 (0x00000006)
ROUND_HALF_UP
public static final int ROUND_HALF_UP
This constant was deprecated
in API level 33.
Use RoundingMode#HALF_UP
instead.
Rounding mode to round towards "nearest neighbor"
unless both neighbors are equidistant, in which case round up.
Behaves as for ROUND_UP
if the discarded fraction is
≥ 0.5; otherwise, behaves as for ROUND_DOWN
. Note
that this is the rounding mode that most of us were taught in
grade school.
Constant Value: 4 (0x00000004)
ROUND_UNNECESSARY
public static final int ROUND_UNNECESSARY
This constant was deprecated
in API level 33.
Use RoundingMode#UNNECESSARY
instead.
Rounding mode to assert that the requested operation has an exact
result, hence no rounding is necessary. If this rounding mode is
specified on an operation that yields an inexact result, an
ArithmeticException
is thrown.
Constant Value: 7 (0x00000007)
ROUND_UP
public static final int ROUND_UP
This constant was deprecated
in API level 33.
Use RoundingMode#UP
instead.
Rounding mode to round away from zero. Always increments the digit prior to a nonzero discarded fraction. Note that this rounding mode never decreases the magnitude of the calculated value.
Constant Value: 0 (0x00000000)
Fields
Public constructors
BigDecimal
public BigDecimal (char[] in, int offset, int len)
Translates a character array representation of a
BigDecimal
into a BigDecimal
, accepting the
same sequence of characters as the BigDecimal(java.lang.String)
constructor, while allowing a sub-array to be specified.
Implementation Note:
- If the sequence of characters is already available
within a character array, using this constructor is faster than
converting the
char
array to string and using theBigDecimal(String)
constructor.
Parameters | |
---|---|
in |
char : char array that is the source of characters. |
offset |
int : first character in the array to inspect. |
len |
int : number of characters to consider. |
Throws | |
---|---|
NumberFormatException |
if in is not a valid
representation of a BigDecimal or the defined subarray
is not wholly within in . |
BigDecimal
public BigDecimal (char[] in, int offset, int len, MathContext mc)
Translates a character array representation of a
BigDecimal
into a BigDecimal
, accepting the
same sequence of characters as the BigDecimal(java.lang.String)
constructor, while allowing a sub-array to be specified and
with rounding according to the context settings.
Implementation Note:
- If the sequence of characters is already available
within a character array, using this constructor is faster than
converting the
char
array to string and using theBigDecimal(String)
constructor.
Parameters | |
---|---|
in |
char : char array that is the source of characters. |
offset |
int : first character in the array to inspect. |
len |
int : number of characters to consider. |
mc |
MathContext : the context to use. |
Throws | |
---|---|
NumberFormatException |
if in is not a valid
representation of a BigDecimal or the defined subarray
is not wholly within in . |
BigDecimal
public BigDecimal (char[] in)
Translates a character array representation of a
BigDecimal
into a BigDecimal
, accepting the
same sequence of characters as the BigDecimal(java.lang.String)
constructor.
Implementation Note:
- If the sequence of characters is already available
as a character array, using this constructor is faster than
converting the
char
array to string and using theBigDecimal(String)
constructor.
Parameters | |
---|---|
in |
char : char array that is the source of characters. |
Throws | |
---|---|
NumberFormatException |
if in is not a valid
representation of a BigDecimal . |
BigDecimal
public BigDecimal (char[] in, MathContext mc)
Translates a character array representation of a
BigDecimal
into a BigDecimal
, accepting the
same sequence of characters as the BigDecimal(java.lang.String)
constructor and with rounding according to the context
settings.
Implementation Note:
- If the sequence of characters is already available
as a character array, using this constructor is faster than
converting the
char
array to string and using theBigDecimal(String)
constructor.
Parameters | |
---|---|
in |
char : char array that is the source of characters. |
mc |
MathContext : the context to use. |
Throws | |
---|---|
NumberFormatException |
if in is not a valid
representation of a BigDecimal . |
BigDecimal
public BigDecimal (String val)
Translates the string representation of a BigDecimal
into a BigDecimal
. The string representation consists
of an optional sign, '+'
( '\u002B'
) or
'-'
('\u002D'
), followed by a sequence of
zero or more decimal digits ("the integer"), optionally
followed by a fraction, optionally followed by an exponent.
The fraction consists of a decimal point followed by zero or more decimal digits. The string must contain at least one digit in either the integer or the fraction. The number formed by the sign, the integer and the fraction is referred to as the significand.
The exponent consists of the character 'e'
('\u0065'
) or 'E'
('\u0045'
)
followed by one or more decimal digits. The value of the
exponent must lie between -Integer#MAX_VALUE
(Integer.MIN_VALUE
+1) and Integer#MAX_VALUE
, inclusive.
More formally, the strings this constructor accepts are described by the following grammar:
- BigDecimalString:
- Signopt Significand Exponentopt
- Sign:
+
-
- Significand:
- IntegerPart
.
FractionPartopt.
FractionPart- IntegerPart
- IntegerPart:
- Digits
- FractionPart:
- Digits
- Exponent:
- ExponentIndicator SignedInteger
- ExponentIndicator:
e
E
- SignedInteger:
- Signopt Digits
- Digits:
- Digit
- Digits Digit
- Digit:
- any character for which
Character#isDigit
returnstrue
, including 0, 1, 2 ...
The scale of the returned BigDecimal
will be the
number of digits in the fraction, or zero if the string
contains no decimal point, subject to adjustment for any
exponent; if the string contains an exponent, the exponent is
subtracted from the scale. The value of the resulting scale
must lie between Integer.MIN_VALUE
and
Integer.MAX_VALUE
, inclusive.
The character-to-digit mapping is provided by Character.digit(char, int)
set to convert to radix 10. The
String may not contain any extraneous characters (whitespace,
for example).
Examples:
The value of the returned BigDecimal
is equal to
significand × 10 exponent.
For each string on the left, the resulting representation
[BigInteger
, scale
] is shown on the right.
"0" [0,0] "0.00" [0,2] "123" [123,0] "-123" [-123,0] "1.23E3" [123,-1] "1.23E+3" [123,-1] "12.3E+7" [123,-6] "12.0" [120,1] "12.3" [123,1] "0.00123" [123,5] "-1.23E-12" [-123,14] "1234.5E-4" [12345,5] "0E+7" [0,-7] "-0" [0,0]
API Note:
- For values other than
float
anddouble
NaN and ±Infinity, this constructor is compatible with the values returned byFloat#toString
andDouble#toString
. This is generally the preferred way to convert afloat
ordouble
into a BigDecimal, as it doesn't suffer from the unpredictability of theBigDecimal(double)
constructor.
Parameters | |
---|---|
val |
String : String representation of BigDecimal . |
Throws | |
---|---|
NumberFormatException |
if val is not a valid
representation of a BigDecimal . |
BigDecimal
public BigDecimal (String val, MathContext mc)
Translates the string representation of a BigDecimal
into a BigDecimal
, accepting the same strings as the
BigDecimal(java.lang.String)
constructor, with rounding
according to the context settings.
Parameters | |
---|---|
val |
String : string representation of a BigDecimal . |
mc |
MathContext : the context to use. |
Throws | |
---|---|
NumberFormatException |
if val is not a valid
representation of a BigDecimal. |
BigDecimal
public BigDecimal (double val)
Translates a double
into a BigDecimal
which
is the exact decimal representation of the double
's
binary floating-point value. The scale of the returned
BigDecimal
is the smallest value such that
(10scale × val)
is an integer.
Notes:
-
The results of this constructor can be somewhat unpredictable.
One might assume that writing
new BigDecimal(0.1)
in Java creates aBigDecimal
which is exactly equal to 0.1 (an unscaled value of 1, with a scale of 1), but it is actually equal to 0.1000000000000000055511151231257827021181583404541015625. This is because 0.1 cannot be represented exactly as adouble
(or, for that matter, as a binary fraction of any finite length). Thus, the value that is being passed in to the constructor is not exactly equal to 0.1, appearances notwithstanding. -
The
String
constructor, on the other hand, is perfectly predictable: writingnew BigDecimal("0.1")
creates aBigDecimal
which is exactly equal to 0.1, as one would expect. Therefore, it is generally recommended that the String constructor be used in preference to this one. -
When a
double
must be used as a source for aBigDecimal
, note that this constructor provides an exact conversion; it does not give the same result as converting thedouble
to aString
using theDouble#toString(double)
method and then using theBigDecimal(java.lang.String)
constructor. To get that result, use thestatic
valueOf(double)
method.
Parameters | |
---|---|
val |
double : double value to be converted to
BigDecimal . |
Throws | |
---|---|
NumberFormatException |
if val is infinite or NaN. |
BigDecimal
public BigDecimal (double val, MathContext mc)
Translates a double
into a BigDecimal
, with
rounding according to the context settings. The scale of the
BigDecimal
is the smallest value such that
(10scale × val)
is an integer.
The results of this constructor can be somewhat unpredictable
and its use is generally not recommended; see the notes under
the BigDecimal(double)
constructor.
Parameters | |
---|---|
val |
double : double value to be converted to
BigDecimal . |
mc |
MathContext : the context to use. |
Throws | |
---|---|
NumberFormatException |
if val is infinite or NaN. |
BigDecimal
public BigDecimal (BigInteger val)
Translates a BigInteger
into a BigDecimal
.
The scale of the BigDecimal
is zero.
Parameters | |
---|---|
val |
BigInteger : BigInteger value to be converted to
BigDecimal . |
BigDecimal
public BigDecimal (BigInteger val, MathContext mc)
Translates a BigInteger
into a BigDecimal
rounding according to the context settings. The scale of the
BigDecimal
is zero.
Parameters | |
---|---|
val |
BigInteger : BigInteger value to be converted to
BigDecimal . |
mc |
MathContext : the context to use. |
BigDecimal
public BigDecimal (BigInteger unscaledVal, int scale)
Translates a BigInteger
unscaled value and an
int
scale into a BigDecimal
. The value of
the BigDecimal
is
(unscaledVal × 10-scale)
.
Parameters | |
---|---|
unscaledVal |
BigInteger : unscaled value of the BigDecimal . |
scale |
int : scale of the BigDecimal . |
BigDecimal
public BigDecimal (BigInteger unscaledVal, int scale, MathContext mc)
Translates a BigInteger
unscaled value and an
int
scale into a BigDecimal
, with rounding
according to the context settings. The value of the
BigDecimal
is (unscaledVal ×
10-scale)
, rounded according to the
precision
and rounding mode settings.
Parameters | |
---|---|
unscaledVal |
BigInteger : unscaled value of the BigDecimal . |
scale |
int : scale of the BigDecimal . |
mc |
MathContext : the context to use. |
BigDecimal
public BigDecimal (int val)
Translates an int
into a BigDecimal
. The
scale of the BigDecimal
is zero.
Parameters | |
---|---|
val |
int : int value to be converted to
BigDecimal . |
BigDecimal
public BigDecimal (int val, MathContext mc)
Translates an int
into a BigDecimal
, with
rounding according to the context settings. The scale of the
BigDecimal
, before any rounding, is zero.
Parameters | |
---|---|
val |
int : int value to be converted to BigDecimal . |
mc |
MathContext : the context to use. |
BigDecimal
public BigDecimal (long val)
Translates a long
into a BigDecimal
. The
scale of the BigDecimal
is zero.
Parameters | |
---|---|
val |
long : long value to be converted to BigDecimal . |
BigDecimal
public BigDecimal (long val, MathContext mc)
Translates a long
into a BigDecimal
, with
rounding according to the context settings. The scale of the
BigDecimal
, before any rounding, is zero.
Parameters | |
---|---|
val |
long : long value to be converted to BigDecimal . |
mc |
MathContext : the context to use. |
Public methods
abs
public BigDecimal abs (MathContext mc)
Returns a BigDecimal
whose value is the absolute value
of this BigDecimal
, with rounding according to the
context settings.
Parameters | |
---|---|
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
abs(this) , rounded as necessary. |
abs
public BigDecimal abs ()
Returns a BigDecimal
whose value is the absolute value
of this BigDecimal
, and whose scale is
this.scale()
.
Returns | |
---|---|
BigDecimal |
abs(this) |
add
public BigDecimal add (BigDecimal augend)
Returns a BigDecimal
whose value is (this +
augend)
, and whose scale is max(this.scale(),
augend.scale())
.
Parameters | |
---|---|
augend |
BigDecimal : value to be added to this BigDecimal . |
Returns | |
---|---|
BigDecimal |
this + augend |
add
public BigDecimal add (BigDecimal augend, MathContext mc)
Returns a BigDecimal
whose value is (this + augend)
,
with rounding according to the context settings.
If either number is zero and the precision setting is nonzero then
the other number, rounded if necessary, is used as the result.
Parameters | |
---|---|
augend |
BigDecimal : value to be added to this BigDecimal . |
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
this + augend , rounded as necessary. |
byteValueExact
public byte byteValueExact ()
Converts this BigDecimal
to a byte
, checking
for lost information. If this BigDecimal
has a
nonzero fractional part or is out of the possible range for a
byte
result then an ArithmeticException
is
thrown.
Returns | |
---|---|
byte |
this BigDecimal converted to a byte . |
Throws | |
---|---|
ArithmeticException |
if this has a nonzero
fractional part, or will not fit in a byte . |
compareTo
public int compareTo (BigDecimal val)
Compares this BigDecimal
numerically with the specified
BigDecimal
. Two BigDecimal
objects that are
equal in value but have a different scale (like 2.0 and 2.00)
are considered equal by this method. Such values are in the
same cohort.
This method is provided in preference to individual methods for
each of the six boolean comparison operators (<, ==,
>, >=, !=, <=). The suggested
idiom for performing these comparisons is: (x.compareTo(y)
<op> 0)
, where
<op> is one of the six comparison operators.
API Note:
- Note: this class has a natural ordering that is inconsistent with equals.
Parameters | |
---|---|
val |
BigDecimal : BigDecimal to which this BigDecimal is
to be compared. |
Returns | |
---|---|
int |
-1, 0, or 1 as this BigDecimal is numerically
less than, equal to, or greater than val . |
divide
public BigDecimal divide (BigDecimal divisor, int scale, int roundingMode)
This method was deprecated
in API level 33.
The method divide(java.math.BigDecimal, int, java.math.RoundingMode)
should be used in preference to this legacy method.
Returns a BigDecimal
whose value is (this /
divisor)
, and whose scale is as specified. If rounding must
be performed to generate a result with the specified scale, the
specified rounding mode is applied.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
scale |
int : scale of the BigDecimal quotient to be returned. |
roundingMode |
int : rounding mode to apply. |
Returns | |
---|---|
BigDecimal |
this / divisor |
Throws | |
---|---|
ArithmeticException |
if divisor is zero,
roundingMode==ROUND_UNNECESSARY and
the specified scale is insufficient to represent the result
of the division exactly. |
IllegalArgumentException |
if roundingMode does not
represent a valid rounding mode. |
divide
public BigDecimal divide (BigDecimal divisor, int scale, RoundingMode roundingMode)
Returns a BigDecimal
whose value is (this /
divisor)
, and whose scale is as specified. If rounding must
be performed to generate a result with the specified scale, the
specified rounding mode is applied.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
scale |
int : scale of the BigDecimal quotient to be returned. |
roundingMode |
RoundingMode : rounding mode to apply. |
Returns | |
---|---|
BigDecimal |
this / divisor |
Throws | |
---|---|
ArithmeticException |
if divisor is zero,
roundingMode==RoundingMode.UNNECESSARY and
the specified scale is insufficient to represent the result
of the division exactly. |
divide
public BigDecimal divide (BigDecimal divisor, int roundingMode)
This method was deprecated
in API level 33.
The method divide(java.math.BigDecimal, java.math.RoundingMode)
should be used in preference to this legacy method.
Returns a BigDecimal
whose value is (this /
divisor)
, and whose scale is this.scale()
. If
rounding must be performed to generate a result with the given
scale, the specified rounding mode is applied.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
roundingMode |
int : rounding mode to apply. |
Returns | |
---|---|
BigDecimal |
this / divisor |
Throws | |
---|---|
ArithmeticException |
if divisor==0 , or
roundingMode==ROUND_UNNECESSARY and
this.scale() is insufficient to represent the result
of the division exactly. |
IllegalArgumentException |
if roundingMode does not
represent a valid rounding mode. |
divide
public BigDecimal divide (BigDecimal divisor, MathContext mc)
Returns a BigDecimal
whose value is (this /
divisor)
, with rounding according to the context settings.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
this / divisor , rounded as necessary. |
Throws | |
---|---|
ArithmeticException |
if the result is inexact but the
rounding mode is UNNECESSARY or
mc.precision == 0 and the quotient has a
non-terminating decimal expansion,including dividing by zero |
divide
public BigDecimal divide (BigDecimal divisor, RoundingMode roundingMode)
Returns a BigDecimal
whose value is (this /
divisor)
, and whose scale is this.scale()
. If
rounding must be performed to generate a result with the given
scale, the specified rounding mode is applied.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
roundingMode |
RoundingMode : rounding mode to apply. |
Returns | |
---|---|
BigDecimal |
this / divisor |
Throws | |
---|---|
ArithmeticException |
if divisor==0 , or
roundingMode==RoundingMode.UNNECESSARY and
this.scale() is insufficient to represent the result
of the division exactly. |
divide
public BigDecimal divide (BigDecimal divisor)
Returns a BigDecimal
whose value is (this /
divisor)
, and whose preferred scale is (this.scale() -
divisor.scale())
; if the exact quotient cannot be
represented (because it has a non-terminating decimal
expansion) an ArithmeticException
is thrown.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
Returns | |
---|---|
BigDecimal |
this / divisor |
Throws | |
---|---|
ArithmeticException |
if the exact quotient does not have a terminating decimal expansion, including dividing by zero |
divideAndRemainder
public BigDecimal[] divideAndRemainder (BigDecimal divisor, MathContext mc)
Returns a two-element BigDecimal
array containing the
result of divideToIntegralValue
followed by the result of
remainder
on the two operands calculated with rounding
according to the context settings.
Note that if both the integer quotient and remainder are
needed, this method is faster than using the
divideToIntegralValue
and remainder
methods
separately because the division need only be carried out once.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided,
and the remainder computed. |
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal[] |
a two element BigDecimal array: the quotient
(the result of divideToIntegralValue ) is the
initial element and the remainder is the final element. |
Throws | |
---|---|
ArithmeticException |
if divisor==0 |
ArithmeticException |
if the result is inexact but the
rounding mode is UNNECESSARY , or mc.precision
> 0 and the result of this.divideToIntegralValue(divisor) would
require a precision of more than mc.precision digits. |
divideAndRemainder
public BigDecimal[] divideAndRemainder (BigDecimal divisor)
Returns a two-element BigDecimal
array containing the
result of divideToIntegralValue
followed by the result of
remainder
on the two operands.
Note that if both the integer quotient and remainder are
needed, this method is faster than using the
divideToIntegralValue
and remainder
methods
separately because the division need only be carried out once.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided,
and the remainder computed. |
Returns | |
---|---|
BigDecimal[] |
a two element BigDecimal array: the quotient
(the result of divideToIntegralValue ) is the initial element
and the remainder is the final element. |
Throws | |
---|---|
ArithmeticException |
if divisor==0 |
divideToIntegralValue
public BigDecimal divideToIntegralValue (BigDecimal divisor, MathContext mc)
Returns a BigDecimal
whose value is the integer part
of (this / divisor)
. Since the integer part of the
exact quotient does not depend on the rounding mode, the
rounding mode does not affect the values returned by this
method. The preferred scale of the result is
(this.scale() - divisor.scale())
. An
ArithmeticException
is thrown if the integer part of
the exact quotient needs more than mc.precision
digits.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
The integer part of this / divisor . |
Throws | |
---|---|
ArithmeticException |
if divisor==0 |
ArithmeticException |
if mc.precision > 0 and the result
requires a precision of more than mc.precision digits. |
divideToIntegralValue
public BigDecimal divideToIntegralValue (BigDecimal divisor)
Returns a BigDecimal
whose value is the integer part
of the quotient (this / divisor)
rounded down. The
preferred scale of the result is (this.scale() -
divisor.scale())
.
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
Returns | |
---|---|
BigDecimal |
The integer part of this / divisor . |
Throws | |
---|---|
ArithmeticException |
if divisor==0 |
doubleValue
public double doubleValue ()
Converts this BigDecimal
to a double
.
This conversion is similar to the
narrowing primitive conversion from double
to
float
as defined in
The Java Language Specification:
if this BigDecimal
has too great a
magnitude represent as a double
, it will be
converted to Double#NEGATIVE_INFINITY
or Double.POSITIVE_INFINITY
as appropriate. Note that even when
the return value is finite, this conversion can lose
information about the precision of the BigDecimal
value.
Returns | |
---|---|
double |
this BigDecimal converted to a double . |
equals
public boolean equals (Object x)
Compares this BigDecimal
with the specified Object
for equality. Unlike compareTo
, this method considers two BigDecimal
objects equal only if they are equal in value and
scale. Therefore 2.0 is not equal to 2.00 when compared by this
method since the former has [BigInteger
, scale
]
components equal to [20, 1] while the latter has components
equal to [200, 2].
API Note:
- One example that shows how 2.0 and 2.00 are not
substitutable for each other under some arithmetic operations
are the two expressions:
new BigDecimal("2.0" ).divide(BigDecimal.valueOf(3), HALF_UP)
which evaluates to 0.7 and
new BigDecimal("2.00").divide(BigDecimal.valueOf(3), HALF_UP)
which evaluates to 0.67.
Parameters | |
---|---|
x |
Object : Object to which this BigDecimal is
to be compared. |
Returns | |
---|---|
boolean |
true if and only if the specified Object is a
BigDecimal whose value and scale are equal to this
BigDecimal 's. |
floatValue
public float floatValue ()
Converts this BigDecimal
to a float
.
This conversion is similar to the
narrowing primitive conversion from double
to
float
as defined in
The Java Language Specification:
if this BigDecimal
has too great a
magnitude to represent as a float
, it will be
converted to Float#NEGATIVE_INFINITY
or Float.POSITIVE_INFINITY
as appropriate. Note that even when
the return value is finite, this conversion can lose
information about the precision of the BigDecimal
value.
Returns | |
---|---|
float |
this BigDecimal converted to a float . |
hashCode
public int hashCode ()
Returns the hash code for this BigDecimal
.
The hash code is computed as a function of the unscaled value and the scale of this BigDecimal
.
API Note:
- Two
BigDecimal
objects that are numerically equal but differ in scale (like 2.0 and 2.00) will generally not have the same hash code.
Returns | |
---|---|
int |
hash code for this BigDecimal . |
See also:
intValue
public int intValue ()
Converts this BigDecimal
to an int
.
This conversion is analogous to the
narrowing primitive conversion from double
to
short
as defined in
The Java Language Specification:
any fractional part of this
BigDecimal
will be discarded, and if the resulting
"BigInteger
" is too big to fit in an
int
, only the low-order 32 bits are returned.
Note that this conversion can lose information about the
overall magnitude and precision of this BigDecimal
value as well as return a result with the opposite sign.
Returns | |
---|---|
int |
this BigDecimal converted to an int . |
intValueExact
public int intValueExact ()
Converts this BigDecimal
to an int
, checking
for lost information. If this BigDecimal
has a
nonzero fractional part or is out of the possible range for an
int
result then an ArithmeticException
is
thrown.
Returns | |
---|---|
int |
this BigDecimal converted to an int . |
Throws | |
---|---|
ArithmeticException |
if this has a nonzero
fractional part, or will not fit in an int . |
longValue
public long longValue ()
Converts this BigDecimal
to a long
.
This conversion is analogous to the
narrowing primitive conversion from double
to
short
as defined in
The Java Language Specification:
any fractional part of this
BigDecimal
will be discarded, and if the resulting
"BigInteger
" is too big to fit in a
long
, only the low-order 64 bits are returned.
Note that this conversion can lose information about the
overall magnitude and precision of this BigDecimal
value as well
as return a result with the opposite sign.
Returns | |
---|---|
long |
this BigDecimal converted to a long . |
longValueExact
public long longValueExact ()
Converts this BigDecimal
to a long
, checking
for lost information. If this BigDecimal
has a
nonzero fractional part or is out of the possible range for a
long
result then an ArithmeticException
is
thrown.
Returns | |
---|---|
long |
this BigDecimal converted to a long . |
Throws | |
---|---|
ArithmeticException |
if this has a nonzero
fractional part, or will not fit in a long . |
max
public BigDecimal max (BigDecimal val)
Returns the maximum of this BigDecimal
and val
.
Parameters | |
---|---|
val |
BigDecimal : value with which the maximum is to be computed. |
Returns | |
---|---|
BigDecimal |
the BigDecimal whose value is the greater of this
BigDecimal and val . If they are equal,
as defined by the compareTo
method, this is returned. |
See also:
min
public BigDecimal min (BigDecimal val)
Returns the minimum of this BigDecimal
and
val
.
Parameters | |
---|---|
val |
BigDecimal : value with which the minimum is to be computed. |
Returns | |
---|---|
BigDecimal |
the BigDecimal whose value is the lesser of this
BigDecimal and val . If they are equal,
as defined by the compareTo
method, this is returned. |
See also:
movePointLeft
public BigDecimal movePointLeft (int n)
Returns a BigDecimal
which is equivalent to this one
with the decimal point moved n
places to the left. If
n
is non-negative, the call merely adds n
to
the scale. If n
is negative, the call is equivalent
to movePointRight(-n)
. The BigDecimal
returned by this call has value (this ×
10-n)
and scale max(this.scale()+n,
0)
.
Parameters | |
---|---|
n |
int : number of places to move the decimal point to the left. |
Returns | |
---|---|
BigDecimal |
a BigDecimal which is equivalent to this one with the
decimal point moved n places to the left. |
Throws | |
---|---|
ArithmeticException |
if scale overflows. |
movePointRight
public BigDecimal movePointRight (int n)
Returns a BigDecimal
which is equivalent to this one
with the decimal point moved n
places to the right.
If n
is non-negative, the call merely subtracts
n
from the scale. If n
is negative, the call
is equivalent to movePointLeft(-n)
. The
BigDecimal
returned by this call has value (this
× 10n)
and scale max(this.scale()-n,
0)
.
Parameters | |
---|---|
n |
int : number of places to move the decimal point to the right. |
Returns | |
---|---|
BigDecimal |
a BigDecimal which is equivalent to this one
with the decimal point moved n places to the right. |
Throws | |
---|---|
ArithmeticException |
if scale overflows. |
multiply
public BigDecimal multiply (BigDecimal multiplicand, MathContext mc)
Returns a BigDecimal
whose value is (this ×
multiplicand)
, with rounding according to the context settings.
Parameters | |
---|---|
multiplicand |
BigDecimal : value to be multiplied by this BigDecimal . |
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
this * multiplicand , rounded as necessary. |
multiply
public BigDecimal multiply (BigDecimal multiplicand)
Returns a BigDecimal
whose value is (this ×
multiplicand)
, and whose scale is (this.scale() +
multiplicand.scale())
.
Parameters | |
---|---|
multiplicand |
BigDecimal : value to be multiplied by this BigDecimal . |
Returns | |
---|---|
BigDecimal |
this * multiplicand |
negate
public BigDecimal negate ()
Returns a BigDecimal
whose value is (-this)
,
and whose scale is this.scale()
.
Returns | |
---|---|
BigDecimal |
-this . |
negate
public BigDecimal negate (MathContext mc)
Returns a BigDecimal
whose value is (-this)
,
with rounding according to the context settings.
Parameters | |
---|---|
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
-this , rounded as necessary. |
plus
public BigDecimal plus ()
Returns a BigDecimal
whose value is (+this)
, and whose
scale is this.scale()
.
This method, which simply returns this BigDecimal
is included for symmetry with the unary minus method negate()
.
Returns | |
---|---|
BigDecimal |
this . |
See also:
plus
public BigDecimal plus (MathContext mc)
Returns a BigDecimal
whose value is (+this)
,
with rounding according to the context settings.
The effect of this method is identical to that of the round(java.math.MathContext)
method.
Parameters | |
---|---|
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
this , rounded as necessary. A zero result will
have a scale of 0. |
See also:
pow
public BigDecimal pow (int n, MathContext mc)
Returns a BigDecimal
whose value is
(thisn)
. The current implementation uses
the core algorithm defined in ANSI standard X3.274-1996 with
rounding according to the context settings. In general, the
returned numerical value is within two ulps of the exact
numerical value for the chosen precision. Note that future
releases may use a different algorithm with a decreased
allowable error bound and increased allowable exponent range.
The X3.274-1996 algorithm is:
- An
ArithmeticException
exception is thrown ifabs(n) > 999999999
mc.precision == 0
andn < 0
mc.precision > 0
andn
has more thanmc.precision
decimal digits
- if
n
is zero,ONE
is returned even ifthis
is zero, otherwise- if
n
is positive, the result is calculated via the repeated squaring technique into a single accumulator. The individual multiplications with the accumulator use the same math context settings as inmc
except for a precision increased tomc.precision + elength + 1
whereelength
is the number of decimal digits inn
. - if
n
is negative, the result is calculated as ifn
were positive; this value is then divided into one using the working precision specified above. - The final value from either the positive or negative case is then rounded to the destination precision.
- if
Parameters | |
---|---|
n |
int : power to raise this BigDecimal to. |
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
thisn using the ANSI standard X3.274-1996
algorithm |
Throws | |
---|---|
ArithmeticException |
if the result is inexact but the
rounding mode is UNNECESSARY , or n is out
of range. |
pow
public BigDecimal pow (int n)
Returns a BigDecimal
whose value is
(thisn)
, The power is computed exactly, to
unlimited precision.
The parameter n
must be in the range 0 through
999999999, inclusive. ZERO.pow(0)
returns ONE
.
Note that future releases may expand the allowable exponent
range of this method.
Parameters | |
---|---|
n |
int : power to raise this BigDecimal to. |
Returns | |
---|---|
BigDecimal |
thisn |
Throws | |
---|---|
ArithmeticException |
if n is out of range. |
precision
public int precision ()
Returns the precision of this BigDecimal
. (The
precision is the number of digits in the unscaled value.)
The precision of a zero value is 1.
Returns | |
---|---|
int |
the precision of this BigDecimal . |
remainder
public BigDecimal remainder (BigDecimal divisor)
Returns a BigDecimal
whose value is (this % divisor)
.
The remainder is given by
this.subtract(this.divideToIntegralValue(divisor).multiply(divisor))
.
Note that this is not the modulo operation (the result can be
negative).
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
Returns | |
---|---|
BigDecimal |
this % divisor . |
Throws | |
---|---|
ArithmeticException |
if divisor==0 |
remainder
public BigDecimal remainder (BigDecimal divisor, MathContext mc)
Returns a BigDecimal
whose value is (this %
divisor)
, with rounding according to the context settings.
The MathContext
settings affect the implicit divide
used to compute the remainder. The remainder computation
itself is by definition exact. Therefore, the remainder may
contain more than mc.getPrecision()
digits.
The remainder is given by
this.subtract(this.divideToIntegralValue(divisor,
mc).multiply(divisor))
. Note that this is not the modulo
operation (the result can be negative).
Parameters | |
---|---|
divisor |
BigDecimal : value by which this BigDecimal is to be divided. |
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
this % divisor , rounded as necessary. |
Throws | |
---|---|
ArithmeticException |
if divisor==0 |
ArithmeticException |
if the result is inexact but the
rounding mode is UNNECESSARY , or mc.precision
> 0 and the result of this.divideToIntegralValue(divisor) would
require a precision of more than mc.precision digits. |
round
public BigDecimal round (MathContext mc)
Returns a BigDecimal
rounded according to the
MathContext
settings. If the precision setting is 0 then
no rounding takes place.
The effect of this method is identical to that of the
plus(java.math.MathContext)
method.
Parameters | |
---|---|
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
a BigDecimal rounded according to the
MathContext settings. |
See also:
scale
public int scale ()
Returns the scale of this BigDecimal
. If zero
or positive, the scale is the number of digits to the right of
the decimal point. If negative, the unscaled value of the
number is multiplied by ten to the power of the negation of the
scale. For example, a scale of -3
means the unscaled
value is multiplied by 1000.
Returns | |
---|---|
int |
the scale of this BigDecimal . |
scaleByPowerOfTen
public BigDecimal scaleByPowerOfTen (int n)
Returns a BigDecimal whose numerical value is equal to
(this
* 10n). The scale of
the result is (this.scale() - n)
.
Parameters | |
---|---|
n |
int : the exponent power of ten to scale by |
Returns | |
---|---|
BigDecimal |
a BigDecimal whose numerical value is equal to
(this * 10n) |
Throws | |
---|---|
ArithmeticException |
if the scale would be outside the range of a 32-bit integer. |
setScale
public BigDecimal setScale (int newScale, int roundingMode)
This method was deprecated
in API level 33.
The method setScale(int, java.math.RoundingMode)
should
be used in preference to this legacy method.
Returns a BigDecimal
whose scale is the specified
value, and whose unscaled value is determined by multiplying or
dividing this BigDecimal
's unscaled value by the
appropriate power of ten to maintain its overall value. If the
scale is reduced by the operation, the unscaled value must be
divided (rather than multiplied), and the value may be changed;
in this case, the specified rounding mode is applied to the
division.
API Note:
- Since BigDecimal objects are immutable, calls of
this method do not result in the original object being
modified, contrary to the usual convention of having methods
named
setX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated.
Parameters | |
---|---|
newScale |
int : scale of the BigDecimal value to be returned. |
roundingMode |
int : The rounding mode to apply. |
Returns | |
---|---|
BigDecimal |
a BigDecimal whose scale is the specified value,
and whose unscaled value is determined by multiplying or
dividing this BigDecimal 's unscaled value by the
appropriate power of ten to maintain its overall value. |
Throws | |
---|---|
ArithmeticException |
if roundingMode==ROUND_UNNECESSARY
and the specified scaling operation would require
rounding. |
IllegalArgumentException |
if roundingMode does not
represent a valid rounding mode. |
setScale
public BigDecimal setScale (int newScale)
Returns a BigDecimal
whose scale is the specified
value, and whose value is numerically equal to this
BigDecimal
's. Throws an ArithmeticException
if this is not possible.
This call is typically used to increase the scale, in which
case it is guaranteed that there exists a BigDecimal
of the specified scale and the correct value. The call can
also be used to reduce the scale if the caller knows that the
BigDecimal
has sufficiently many zeros at the end of
its fractional part (i.e., factors of ten in its integer value)
to allow for the rescaling without changing its value.
This method returns the same result as the two-argument
versions of setScale
, but saves the caller the trouble
of specifying a rounding mode in cases where it is irrelevant.
API Note:
- Since
BigDecimal
objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods namedsetX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated.
Parameters | |
---|---|
newScale |
int : scale of the BigDecimal value to be returned. |
Returns | |
---|---|
BigDecimal |
a BigDecimal whose scale is the specified value, and
whose unscaled value is determined by multiplying or dividing
this BigDecimal 's unscaled value by the appropriate
power of ten to maintain its overall value. |
Throws | |
---|---|
ArithmeticException |
if the specified scaling operation would require rounding. |
setScale
public BigDecimal setScale (int newScale, RoundingMode roundingMode)
Returns a BigDecimal
whose scale is the specified
value, and whose unscaled value is determined by multiplying or
dividing this BigDecimal
's unscaled value by the
appropriate power of ten to maintain its overall value. If the
scale is reduced by the operation, the unscaled value must be
divided (rather than multiplied), and the value may be changed;
in this case, the specified rounding mode is applied to the
division.
API Note:
- Since BigDecimal objects are immutable, calls of
this method do not result in the original object being
modified, contrary to the usual convention of having methods
named
setX
mutate fieldX
. Instead,setScale
returns an object with the proper scale; the returned object may or may not be newly allocated.
Parameters | |
---|---|
newScale |
int : scale of the BigDecimal value to be returned. |
roundingMode |
RoundingMode : The rounding mode to apply. |
Returns | |
---|---|
BigDecimal |
a BigDecimal whose scale is the specified value,
and whose unscaled value is determined by multiplying or
dividing this BigDecimal 's unscaled value by the
appropriate power of ten to maintain its overall value. |
Throws | |
---|---|
ArithmeticException |
if roundingMode==UNNECESSARY
and the specified scaling operation would require
rounding. |
See also:
shortValueExact
public short shortValueExact ()
Converts this BigDecimal
to a short
, checking
for lost information. If this BigDecimal
has a
nonzero fractional part or is out of the possible range for a
short
result then an ArithmeticException
is
thrown.
Returns | |
---|---|
short |
this BigDecimal converted to a short . |
Throws | |
---|---|
ArithmeticException |
if this has a nonzero
fractional part, or will not fit in a short . |
signum
public int signum ()
Returns the signum function of this BigDecimal
.
Returns | |
---|---|
int |
-1, 0, or 1 as the value of this BigDecimal
is negative, zero, or positive. |
sqrt
public BigDecimal sqrt (MathContext mc)
Returns an approximation to the square root of this
with rounding according to the context settings.
The preferred scale of the returned result is equal to
this.scale()/2
. The value of the returned result is
always within one ulp of the exact decimal value for the
precision in question. If the rounding mode is HALF_UP
, HALF_DOWN
, or HALF_EVEN
, the
result is within one half an ulp of the exact decimal value.
Special case:
- The square root of a number numerically equal to
ZERO
is numerically equal toZERO
with a preferred scale according to the general rule above. In particular, forZERO
,ZERO.sqrt(mc).equals(ZERO)
is true with anyMathContext
as an argument.
Parameters | |
---|---|
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
the square root of this . |
Throws | |
---|---|
ArithmeticException |
if this is less than zero. |
ArithmeticException |
if an exact result is requested
(mc.getPrecision()==0 ) and there is no finite decimal
expansion of the exact result |
ArithmeticException |
if
(mc.getRoundingMode()==RoundingMode.UNNECESSARY ) and
the exact result cannot fit in mc.getPrecision()
digits. |
See also:
stripTrailingZeros
public BigDecimal stripTrailingZeros ()
Returns a BigDecimal
which is numerically equal to
this one but with any trailing zeros removed from the
representation. For example, stripping the trailing zeros from
the BigDecimal
value 600.0
, which has
[BigInteger
, scale
] components equal to
[6000, 1], yields 6E2
with [BigInteger
,
scale
] components equal to [6, -2]. If
this BigDecimal is numerically equal to zero, then
BigDecimal.ZERO
is returned.
Returns | |
---|---|
BigDecimal |
a numerically equal BigDecimal with any
trailing zeros removed. |
Throws | |
---|---|
ArithmeticException |
if scale overflows. |
subtract
public BigDecimal subtract (BigDecimal subtrahend)
Returns a BigDecimal
whose value is (this -
subtrahend)
, and whose scale is max(this.scale(),
subtrahend.scale())
.
Parameters | |
---|---|
subtrahend |
BigDecimal : value to be subtracted from this BigDecimal . |
Returns | |
---|---|
BigDecimal |
this - subtrahend |
subtract
public BigDecimal subtract (BigDecimal subtrahend, MathContext mc)
Returns a BigDecimal
whose value is (this - subtrahend)
,
with rounding according to the context settings.
If subtrahend
is zero then this, rounded if necessary, is used as the
result. If this is zero then the result is subtrahend.negate(mc)
.
Parameters | |
---|---|
subtrahend |
BigDecimal : value to be subtracted from this BigDecimal . |
mc |
MathContext : the context to use. |
Returns | |
---|---|
BigDecimal |
this - subtrahend , rounded as necessary. |
toBigInteger
public BigInteger toBigInteger ()
Converts this BigDecimal
to a BigInteger
.
This conversion is analogous to the
narrowing primitive conversion from double
to
long
as defined in
The Java Language Specification:
any fractional part of this
BigDecimal
will be discarded. Note that this
conversion can lose information about the precision of the
BigDecimal
value.
To have an exception thrown if the conversion is inexact (in
other words if a nonzero fractional part is discarded), use the
toBigIntegerExact()
method.
Returns | |
---|---|
BigInteger |
this BigDecimal converted to a BigInteger . |
toBigIntegerExact
public BigInteger toBigIntegerExact ()
Converts this BigDecimal
to a BigInteger
,
checking for lost information. An exception is thrown if this
BigDecimal
has a nonzero fractional part.
Returns | |
---|---|
BigInteger |
this BigDecimal converted to a BigInteger . |
Throws | |
---|---|
ArithmeticException |
if this has a nonzero
fractional part. |
toEngineeringString
public String toEngineeringString ()
Returns a string representation of this BigDecimal
,
using engineering notation if an exponent is needed.
Returns a string that represents the BigDecimal
as
described in the toString()
method, except that if
exponential notation is used, the power of ten is adjusted to
be a multiple of three (engineering notation) such that the
integer part of nonzero values will be in the range 1 through
999. If exponential notation is used for zero values, a
decimal point and one or two fractional zero digits are used so
that the scale of the zero value is preserved. Note that
unlike the output of toString()
, the output of this
method is not guaranteed to recover the same [integer,
scale] pair of this BigDecimal
if the output string is
converting back to a BigDecimal
using the string constructor. The result of this method meets
the weaker constraint of always producing a numerically equal
result from applying the string constructor to the method's output.
Returns | |
---|---|
String |
string representation of this BigDecimal , using
engineering notation if an exponent is needed. |
toPlainString
public String toPlainString ()
Returns a string representation of this BigDecimal
without an exponent field. For values with a positive scale,
the number of digits to the right of the decimal point is used
to indicate scale. For values with a zero or negative scale,
the resulting string is generated as if the value were
converted to a numerically equal value with zero scale and as
if all the trailing zeros of the zero scale value were present
in the result.
The entire string is prefixed by a minus sign character '-'
('\u002D'
) if the unscaled value is less than
zero. No sign character is prefixed if the unscaled value is
zero or positive.
Note that if the result of this method is passed to the
string constructor, only the
numerical value of this BigDecimal
will necessarily be
recovered; the representation of the new BigDecimal
may have a different scale. In particular, if this
BigDecimal
has a negative scale, the string resulting
from this method will have a scale of zero when processed by
the string constructor.
(This method behaves analogously to the toString
method in 1.4 and earlier releases.)
Returns | |
---|---|
String |
a string representation of this BigDecimal
without an exponent field. |
See also:
toString
public String toString ()
Returns the string representation of this BigDecimal
,
using scientific notation if an exponent is needed.
A standard canonical string form of the BigDecimal
is created as though by the following steps: first, the
absolute value of the unscaled value of the BigDecimal
is converted to a string in base ten using the characters
'0'
through '9'
with no leading zeros (except
if its value is zero, in which case a single '0'
character is used).
Next, an adjusted exponent is calculated; this is the
negated scale, plus the number of characters in the converted
unscaled value, less one. That is,
-scale+(ulength-1)
, where ulength
is the
length of the absolute value of the unscaled value in decimal
digits (its precision).
If the scale is greater than or equal to zero and the
adjusted exponent is greater than or equal to -6
, the
number will be converted to a character form without using
exponential notation. In this case, if the scale is zero then
no decimal point is added and if the scale is positive a
decimal point will be inserted with the scale specifying the
number of characters to the right of the decimal point.
'0'
characters are added to the left of the converted
unscaled value as necessary. If no character precedes the
decimal point after this insertion then a conventional
'0'
character is prefixed.
Otherwise (that is, if the scale is negative, or the
adjusted exponent is less than -6
), the number will be
converted to a character form using exponential notation. In
this case, if the converted BigInteger
has more than
one digit a decimal point is inserted after the first digit.
An exponent in character form is then suffixed to the converted
unscaled value (perhaps with inserted decimal point); this
comprises the letter 'E'
followed immediately by the
adjusted exponent converted to a character form. The latter is
in base ten, using the characters '0'
through
'9'
with no leading zeros, and is always prefixed by a
sign character '-'
('\u002D'
) if the
adjusted exponent is negative, '+'
('\u002B'
) otherwise).
Finally, the entire string is prefixed by a minus sign
character '-'
('\u002D'
) if the unscaled
value is less than zero. No sign character is prefixed if the
unscaled value is zero or positive.
Examples:
For each representation [unscaled value, scale] on the left, the resulting string is shown on the right.
[123,0] "123" [-123,0] "-123" [123,-1] "1.23E+3" [123,-3] "1.23E+5" [123,1] "12.3" [123,5] "0.00123" [123,10] "1.23E-8" [-123,12] "-1.23E-10"
- There is a one-to-one mapping between the distinguishable
BigDecimal
values and the result of this conversion. That is, every distinguishableBigDecimal
value (unscaled value and scale) has a unique string representation as a result of usingtoString
. If that string representation is converted back to aBigDecimal
using theBigDecimal(java.lang.String)
constructor, then the original value will be recovered. - The string produced for a given number is always the same;
it is not affected by locale. This means that it can be used
as a canonical string representation for exchanging decimal
data, or as a key for a Hashtable, etc. Locale-sensitive
number formatting and parsing is handled by the
NumberFormat
class and its subclasses. - The
toEngineeringString()
method may be used for presenting numbers with exponents in engineering notation, and thesetScale
method may be used for rounding aBigDecimal
so it has a known number of digits after the decimal point. - The digit-to-character mapping provided by
Character.forDigit
is used.
Returns | |
---|---|
String |
string representation of this BigDecimal . |
ulp
public BigDecimal ulp ()
Returns the size of an ulp, a unit in the last place, of this
BigDecimal
. An ulp of a nonzero BigDecimal
value is the positive distance between this value and the
BigDecimal
value next larger in magnitude with the
same number of digits. An ulp of a zero value is numerically
equal to 1 with the scale of this
. The result is
stored with the same scale as this
so the result
for zero and nonzero values is equal to [1,
this.scale()]
.
Returns | |
---|---|
BigDecimal |
the size of an ulp of this |
unscaledValue
public BigInteger unscaledValue ()
Returns a BigInteger
whose value is the unscaled
value of this BigDecimal
. (Computes (this *
10this.scale())
.)
Returns | |
---|---|
BigInteger |
the unscaled value of this BigDecimal . |
valueOf
public static BigDecimal valueOf (double val)
Translates a double
into a BigDecimal
, using
the double
's canonical string representation provided
by the Double#toString(double)
method.
API Note:
- This is generally the preferred way to convert a
double
(orfloat
) into aBigDecimal
, as the value returned is equal to that resulting from constructing aBigDecimal
from the result of usingDouble.toString(double)
.
Parameters | |
---|---|
val |
double : double to convert to a BigDecimal . |
Returns | |
---|---|
BigDecimal |
a BigDecimal whose value is equal to or approximately
equal to the value of val . |
Throws | |
---|---|
NumberFormatException |
if val is infinite or NaN. |
valueOf
public static BigDecimal valueOf (long val)
Translates a long
value into a BigDecimal
with a scale of zero.
API Note:
- This static factory method is provided in preference
to a (
long
) constructor because it allows for reuse of frequently usedBigDecimal
values.
Parameters | |
---|---|
val |
long : value of the BigDecimal . |
Returns | |
---|---|
BigDecimal |
a BigDecimal whose value is val . |
valueOf
public static BigDecimal valueOf (long unscaledVal, int scale)
Translates a long
unscaled value and an
int
scale into a BigDecimal
.
API Note:
- This static factory method is provided in preference
to a (
long
,int
) constructor because it allows for reuse of frequently usedBigDecimal
values.
Parameters | |
---|---|
unscaledVal |
long : unscaled value of the BigDecimal . |
scale |
int : scale of the BigDecimal . |
Returns | |
---|---|
BigDecimal |
a BigDecimal whose value is
(unscaledVal × 10-scale) . |