Trying to find factors of a number in JS

Question

I am just starting JS, and understand the concept of finding a factor. However, this snippet of code is what I have so far. I have the str variable that outputs nothing but the

Answer 1

Here's an optimized solution using best practices, proper code style/readability, and returns the results in an ordered array.

function getFactors(num) {
    const maxFactorNum = Math.floor(Math.sqrt(num));
    const factorArr = [];
    let count = 0;  //count of factors found < maxFactorNum.

    for (let i = 1; i <= maxFactorNum; i++) {
        //inserting new elements in the middle using splice
        if (num % i === 0) {
            factorArr.splice(count, 0, i);
            let otherFactor = num / i; //the other factor
            if (i != otherFactor) {
                //insert these factors in the front of the array
                factorArr.splice(-count, 0, otherFactor);
            }
            count++;
        }
    }

    //swapping first and last elements
    let lastIndex = factorArr.length - 1;
    let temp = factorArr[lastIndex];
    factorArr[lastIndex] = factorArr[0];
    factorArr[0] = temp;

    return factorArr;
}

console.log(getFactors(100));
console.log(getFactors(240));
console.log(getFactors(600851475143)); //large number used in Project Euler.

I based my answer on the answer written by @Harman