Question

Simple question, how do I get every option when dividing a number? For example:

• 24 by 6 returns 6, 12, 18, 24
• 24 by 4 returns 4, 8, 12, 16, 20, 24
• 24 by 5 returns false

I’ve got a number in my database, for example 2, and my counter, for example 14. That means every time my counter hits the second number, I want to fire my event. So I thought, if I have the solutions 2, 4, 6, etc, and my counter is equal to one of the solutions, I can fire my event.

Answer 1

It’s rather trivial to make.

<?php

/**
 * @param int $number  The beginning number
 * @param int $divider The number dividing by
 *
 * @return array
 * @throws Exception   In case $number is not divisible by $divider
 */
function get_number_sequence($number, $divider) {
    //In case $number is not divisible by $divider, throw an Exception.
    if ($number % $divider !== 0) {
        throw new Exception("$number is not divisible by $divider");
    }
    //Return an array from $divider to $number in steps of $divider.
    $result = range($divider, $number, $divider);
    return $result;
}

/*
 * Testing begins
 */

try {
    echo "<pre>";
    echo implode(", ", get_number_sequence(24, 4)) . PHP_EOL;
    echo implode(", ", get_number_sequence(24, 6)) . PHP_EOL;
    echo implode(", ", get_number_sequence(24, 5)) . PHP_EOL;
    echo "</pre>";
}
catch (Exception $e) {
    echo "Invalid: " . $e->getMessage();
}

Some Points

• Don’t return false if something exceptional happens, use an Exception as shown in the example.
• Use the modulus operator to determine if the number is divisible or not.
• Return an array, not a string. It’s easier to work with.