Arrays.deepToString() in Java with Example (original) (raw)

Last Updated : 25 Nov, 2024

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.

Java `

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
• Examples of Arrays.deepToString() in Java
  • Print a 2D Array with deepToString()
  • Use deepToString() with Single and Multidimensional Arrays

**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 `

// 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 `

// 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() method doesn’t work well for multidimensional arrays.
• deepToString() method prints multidimensional arrays properly.