Listing Factors of Numbers in JavaScript - Math Programming for Kids

What are Factors? | Maths Explanation for JavaScript Kids

Factors are the complete set of integers that will divide a particular number without remainder.
Take 36 as an example, it's complete set are:

1, 2, 3, 4, 6, 9, 12, 18, and 36.

Other than prime numbers, every other number has at least one factor - not considering 1 as factor.
Where there is just one factor, then this factor is the square root of the number in question;
In this guide, we'll explore the math behind factors-of-numbers and walk through how to code a JavaScript algorithm for listing factors in a simple and fun way.

Code Logic for Factorising Numbers in JavaScript - Fun Maths Exercise

Actually, we've been doing factors over the last two demonstrations (lessons).

We can implement a JavaScript algorithm for factorising a number by simply checking for our factors using the square-root of number range.
We'll start from 1 (which is always a factor).
For each found factor, we'll get the corresponding complementary factor by dividing the number (whose factors we are trying to find), by the found factor.
This Math activity and JavaScript script help primary school students understand factorization by listing all factors of a number.

Create a new file; On Notepad++: File, New.
Call it ListFactors.html.
Type out the adjoining JavaScript code for listing factors.

So! JavaScript Fun Practice Exercise - List Factors

As a fun practice exercise, feel free to try out your own different numbers, and see how the JavaScript code lists the factors of those numbers.

JavaScript Code for List Factors

<!DOCTYPE html>

<html lang="en">
    <head>
        <meta charset="utf-8" />
        <title>Listing The Factors Of A Number.</title>
    </head>
    <body>
        <h4>Factors of any number are those numbers that can divide
            the number under question without remainder.</h4>
        <div id="my_factors"></div>

        <script>
            var find_my_factors = 48;
            var found_factors = [];
            // 'count' acts as both index into array 'found_factor' and count of number of factors found
            var count = 0;
            var square_root_range = Math.sqrt(find_my_factors); // Use this range for our loop
            square_root_range = Math.ceil(square_root_range);
            var i = 1;

            /*
             * Loop through 1 to 'find_my_factors' and test for divisibility.
             */
            for (; i < square_root_range; i++) {
                if ((find_my_factors % i) == 0) {
                    found_factors[count++] = i;
                    /* Get the complementing factor by dividing 'find_my_factor' by variable i. */
                    found_factors[count++] = find_my_factors / i;
                }
            }

            // Sort the array in ascending order; Not entirely necessary.
            found_factors.sort(
                    function (a, b) {
                        return a - b;
                    }
            );

            document.getElementById("my_factors").innerHTML =
                    "The factors of " + find_my_factors + " are: <br />" + found_factors.join(", ");
        </script>
    </body>
</html>

I have a better version / See other versions.