How to print 2D Array in Java

In Java, there are several ways to print a 2D array. In this guide, we will see various programs to print 2D array using different approaches:

Note: In the previous tutorial, I have covered how to print an array(1D array).

Printing 2D Arrays

1. Using Arrays.deepToString()

You can use Arrays.deepToString() method to print a 2D array. You can simply pass the reference of 2D array as an argument to this method in order to display all the elements.

import java.util.Arrays;

public class Main {
    public static void main(String[] args) {
        int[][] array = {
            {1, 2, 3},
            {4, 5, 6},
            {7, 8, 9}
        };
        System.out.println(Arrays.deepToString(array));
    }
}

Output:

[[1, 2, 3], [4, 5, 6], [7, 8, 9]]

2. Using Nested Loop

Another simple way of displaying a 2D array is by using nested loops. In this program, we are using nested for-each loops.

public class Main {
    public static void main(String[] args) {
        int[][] array = {
            {1, 2, 3},
            {4, 5, 6},
            {7, 8, 9}
        };
        for (int[] row : array) {
            for (int element : row) {
                System.out.print(element + " ");
            }
            System.out.println();
        }
    }
}

Output:

1 2 3
4 5 6
7 8 9

3. Using Iterator

Another way to print an array is by converting it into a list and then using an iterator to display the elements of the list. In this example, we are using nested iterators.

import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        Integer[][] array = {
            {1, 2, 3},
            {4, 5, 6},
            {7, 8, 9}
        };
        
        for (Integer[] row : array) {
            List<Integer> list = Arrays.asList(row);
            Iterator<Integer> iterator = list.iterator();
            while (iterator.hasNext()) {
                System.out.print(iterator.next() + " ");
            }
            System.out.println();
        }
    }
}

Output:

1 2 3
4 5 6
7 8 9

4. Using Stream

You can use the Stream API to print each element of the array. You can refer Java Stream Tutorial to learn more about Stream.

import java.util.Arrays;

public class Main {
    public static void main(String[] args) {
        int[][] array = {
            {1, 2, 3},
            {4, 5, 6},
            {7, 8, 9}
        };
        
        Arrays.stream(array).forEach(row -> {
            Arrays.stream(row).forEach(element -> System.out.print(element + " "));
            System.out.println();
        });
    }
}

Output:

1 2 3
4 5 6
7 8 9

5. Using Arrays.asList

For 2D arrays, you can convert each row to a list using asList() method and print it. This method belongs to java.util.Arrays class. I have covered some of the commonly used methods here: Java Arrays Methods.

import java.util.Arrays;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        Integer[][] array = {
            {1, 2, 3},
            {4, 5, 6},
            {7, 8, 9}
        };
        
        for (Integer[] row : array) {
            List<Integer> list = Arrays.asList(row);
            System.out.println(list);
        }
    }
}

Output:

[1, 2, 3]
[4, 5, 6]
[7, 8, 9]