Nested Loops

In this lesson, we will look at nested loops in JavaScript. A nested loop is a loop inside another loop. It is often used when working with multiple arrays or with nested arrays. 

Example: We want to print all possible pairs of numbers from two lists:

const numbers1 = [1, 2];
const numbers2 = [3, 4];
for (const number1 of numbers1) {
    for (const number2 of numbers2) {
        console.log(number1 + " " + number2);
    }
}

Output:

1 3
1 4
2 3
2 4

In this example, we iterate through all numbers in the list numbers1 and for each number in this list, we iterate through all numbers in the list numbers2. For each combination of numbers, we print the pair.