Nested Loop

Part of the Fundamentals section of Coddy's Java journey — lesson 48 of 73.

A nested loop is simply a loop inside another loop. The inner loop will complete all its iterations for each single iteration of the outer loop.

A good analogy for this is a clock: for each hour (outer loop), the minute hand (inner loop) must complete its full 60-minute cycle.

Example of a nested loop:

for (int x = 0; x < 2; x++) {
    for (int y = 0; y < 2; y++) {
        System.out.println(x + " " + y);
    }
}

// This will output:
// 0 0
// 0 1
// 1 0
// 1 1

The outer loop (x) runs twice, and for each of those times, the inner loop (y) runs twice.

Challenge

Beginner

Write a program that prints a rectangle of asterisks (*) with a given width and height.

Input: Two integers: width and height

For example:

If width = 5 and height = 3, the output should be:

*****
*****
*****

If width = 4 and height = 6, the output should be:

****
****
****
****
****
****

Cheat sheet

A nested loop is a loop inside another loop. The inner loop completes all its iterations for each single iteration of the outer loop.

Basic nested loop structure:

for (int x = 0; x < 2; x++) {
    for (int y = 0; y < 2; y++) {
        System.out.println(x + " " + y);
    }
}

// Output:
// 0 0
// 0 1
// 1 0
// 1 1

The outer loop runs completely, and for each iteration of the outer loop, the inner loop runs all of its iterations.

Try it yourself

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int width = scanner.nextInt();
        int height = scanner.nextInt();
        // Write your code below

    }
}