How to Convert a String to an Numeric in Java?
In Java programming, there are situations in which we must convert a string of numeric characters into one of the following data types: double, float, long, or int. To execute arithmetic operations and other numerical calculations, this conversion is necessary. We will look at how to convert a string to numeric types in Java in this tutorial.
String to Numeric Conversion in Java
In Java, we may utilize the wrapper classes and their corresponding parse methods to transform a string to a numeric type. For instance, Long.parseLong() for long, Float.parseFloat() for float, Double.parseDouble() for double, and Integer.parseInt() for converting to an int. Managing exceptions is essential because, if the string does not represent a valid numeric value, the conversion can generate a NumberFormatException.
Syntax:
Long varLong=Long.parseLong(str);
int varInt = Integer.parseInt(intString);
float varFloat = Float.parseFloat(floatString);
double varDouble = Double.parseDouble(doubleString);
Convert a String to an Numeric in Java
Let's look at several instances of how to convert various numeric types from a string:
public class StringToNumericExample {
public static void main(String[] args) {
// Example 1: Convert String to int
String intString = "123";
int convertedInt = Integer.parseInt(intString);
System.out.println("Converted int: " + convertedInt);
// Example 2: Convert String to long
String longString = "9876543210";
long convertedLong = Long.parseLong(longString);
System.out.println("Converted long: " + convertedLong);
// Example 3: Convert String to float
String floatString = "45.67";
float convertedFloat = Float.parseFloat(floatString);
System.out.println("Converted float: " + convertedFloat);
// Example 4: Convert String to double
String doubleString = "123.456";
double convertedDouble = Double.parseDouble(doubleString);
System.out.println("Converted double: " + convertedDouble);
}
}
Output
Converted int: 123 Converted long: 9876543210 Converted float: 45.67 Converted double: 123.456
Explanation of the above Program:
- The examples show how to convert strings that represent numerical values to double, float, long, and int.
- For conversion, the parse methods of the corresponding wrapper classes—Integer, Long, Float, and Double—are used.
- After that, the converted numbers are shown on the console.
