findFactorsNumber()

Step 1: Understanding the Problem

The first step is to understand what a factor is: A factor of a number is a number that divides into another number exactly. So in terms of problem solving, we are asked to find all such numbers that can divide a given number without leaving any remainder. In JavaScript, the modulus operator (%) is used to find the remainder of two numbers. If the remainder of the division is zero, it means one number is the factor of the other.

let number = 15;
for(let i = 1; i <= number; i++) {
    if(number % i === 0) {
        console.log(i + ' is a factor of ' + number);
    }
}

Step 2: Function Declaration

Now, let's declare a function named getFactors to perform this task. The above logic of factor calculation is placed inside this function which accepts one parameter - the number for which we need to calculate the factors.

function getFactors(number) {
    for(let i = 1; i <= number; i++) {
        if(number % i === 0) {
            console.log(i + ' is a factor of ' + number);
        }
    }
}

Step 3: Storing the Results

In the current state, the factors are just displayed in the console. Let's instead of logging them, push them into an array which can be returned by the function.

function getFactors(number) {
    let factors = [];
    for(let i = 1; i <= number; i++) {
        if(number % i === 0) {
            factors.push(i);
        }
    }
    return factors;
}

Step 4: Calling the Function

We now call the function getFactors with a number to get its factors.

console.log(getFactors(15)); // Outputs: [1, 3, 5, 15]

Conclusion

The function getFactors successfully finds and returns all the factors of a given number. Here is the full code of the function:

function getFactors(number) {
    let factors = [];
    for(let i = 1; i <= number; i++) {
        if(number % i === 0) {
            factors.push(i);
        }
    }
    return factors;
}
console.log(getFactors(15)); // Outputs: [1, 3, 5, 15]