What is a nested loop in Java and how do I use a foreach loop with it?

What is a nested loop in Java and how do I use a foreach loop with it?

A nested loop in Java is a loop inside another loop. You can use a foreach loop to iterate over collections or arrays within the outer loop.

Can you give me an example of using a foreach loop in a nested loop?

Sure! Here's an example:

int[][] matrix = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
for (int[] row : matrix) {
    for (int num : row) {
        System.out.print(num + " ");
    }
    System.out.println();
}

What does this code do?

This code iterates through a 2D array (matrix) and prints each number in the matrix, row by row.

Are there any performance considerations when using nested loops?

Yes, nested loops can lead to performance issues, especially with large datasets, as the time complexity increases.