Utilizing Nested Loops and Arrays

Welcome to our programming practice lesson! Are you ready for a challenging yet exciting task involving nested loops and arrays? We will unravel the skill of using nested loops to search through two arrays. Brace yourself for a remarkable journey of practical learning. Let's get started!

Your task is to create a function that takes two arrays of integers as input and returns pairs of integers. Each pair should consist of:

1. The first integer from the first array.
2. The second integer from the second array. However, there's a condition: the first integer in the pair must be less than the second integer. The output should be a list of strings, where each string represents a valid pair in the format "first second". The order of the pairs in the output must respect the order of the integers in the input arrays. For example: Given the arrays [1, 3, 7] and [2, 8, 9], the function should return: ["1 2", "1 8", "1 9", "3 8", "3 9", "7 8", "7 9"].

Keep in mind: If no valid pairs exist, the function should return an empty list. If either of the input arrays is empty, the result should also be an empty list.

Let's delve into this task step by step to uncover the solution!

Before venturing into the code, let's decode the problem. Nested looping fits perfectly here.

Start by creating an empty array named result to store our pairs.

function retrievePairs(array1: number[], array2: number[]): string[] {
    let result: string[] = [];

Creating your function and data structure first is a wise strategy!

Now, the focus turns to forming the nested loops. You need to iterate over both arrays, and for this, you'll need nested loops. An outer loop will select one element from the first array, and an inner loop will scan through each element of the second array.

function retrievePairs(array1: number[], array2: number[]): string[] {
    let result: string[] = [];
    // Start of the outer loop: iterating through elements of array1
    for (let i of array1) {
        // Start of the inner loop: iterating through elements
        // of array2 for each element of array1
        for (let j of array2) {
            // Our logic goes here
        }
    }
    return result;
}

In this setup, every element in array1 is represented by i, and for each i, j represents an element in array2.