How to convert integer to Roman number

convert-integer-to-roman.php

<?php
    /**
     * Converts integer to Roman.
     *
     * @param int $integer
     *   Integer to be converted to Roman string.
     *
     * @return string
     */
    public function integerToRoman($integer) {
        // Convert the integer into an integer (just to make sure).
        $integer = intval($integer);
        $result = '';

        // Create a lookup array that contains all of the Roman numerals.
        $lookup = [
            'M' => 1000,
            'CM' => 900,
            'D' => 500,
            'CD' => 400,
            'C' => 100,
            'XC' => 90,
            'L' => 50,
            'XL' => 40,
            'X' => 10,
            'IX' => 9,
            'V' => 5,
            'IV' => 4,
            'I' => 1
        ];

        foreach ($lookup as $roman => $value) {
            // Determine the number of matches.
            $matches = intval($integer / $value);

            // Add the same number of characters to the string.
            $result .= str_repeat($roman, $matches);

            // Set the integer to be the remainder of the integer and the value.
            $integer = $integer % $value;
        }

        // The Roman numeral should be built, return it.
        return $result;
    }