Arrays.deepToString() in Java with Example
The Arrays.deepToString() method comes under the Arrays class in Java. It is used to return a string representation of the “deep contents” of a specified array. It handles multidimensional arrays by including the contents of nested arrays.
Example:
Below is a simple example that uses Arrays.deepToString() to convert a multidimensional array into a readable string format.
import java.util.Arrays;
public class Example {
public static void main(String[] args) {
int[][] arr = { {1, 2, 3},
{4, 5, 6},
{7, 8, 9} };
// using Arrays.deepToString() to
// display the array content
System.out.println("" + Arrays.deepToString(arr));
}
}
Output
[[1, 2, 3], [4, 5, 6], [7, 8, 9]]
Explanation: In this example, the Arrays.deepToString() method prints a 2D array, to get a readable format without manually iterating through the elements.
Table of Content
Syntax of Arrays.deepToString() method
public static String deepToString(Object[] arr)
Parameter: arr: An array whose string representation is needed. It can be a single-dimensional or multi-dimensional array.
Return Type:
- This method returns string representation of array.
- If the array contains other arrays, it prints the elements of those arrays as well.
- If the array is
null, the method returns the string"null".
Examples of Arrays.deepToString() in Java
Print a 2D Array with deepToString()
In this example, we will use the Arrays.deepToString() method to print a two-dimensional array, which will display the nested elements correctly.
// Java program to print 2D array
// using deepToString()
import java.util.Arrays;
public class GfG {
public static void main(String[] args) {
int[][] a = new int[2][2];
a[0][0] = 11;
a[0][1] = 22;
a[1][0] = 33;
a[1][1] = 44;
// print 2D integer array
// using deepToString()
System.out.println(Arrays.deepToString(a));
}
}
Output
[[11, 22], [33, 44]]
Use deepToString() with Single and Multidimensional Arrays
Arrays.deepToString() method works for both single and multidimensional arrays, but does not support primitive type arrays such as int[].
// Java program to demonstrate deepToString() works for
// single-dimensional arrays, but not for primitive arrays
import java.util.Arrays;
public class GFG {
public static void main(String[] args) {
String[] s = new String[] {"practice.geeksforgeeks.org",
"www.geeksforgeeks.org"
};
System.out.println(Arrays.deepToString(s));
Integer [] arr1 = {11, 22, 33, 44};
System.out.println(Arrays.deepToString(arr1));
/* Uncommenting below code would cause error as
deepToString() doesn't work for primitive types
int [] arr2 = {10, 20, 30, 40};
System.out.println(Arrays.deepToString(arr2)); */
}
}
Output
[practice.geeksforgeeks.org, www.geeksforgeeks.org] [11, 22, 33, 44]
toString() vs. deepToString()
toString()methoddoesn’t work well for multidimensional arrays.deepToString()methodprints multidimensional arrays properly.
