<?php
if (!function_exists('generateRandomString')) {
    /**
     * Generates a random string of specified length.
     *
     * @param int $length Length of the random string.
     * @return string The generated random string.
     */
    function generateRandomString($length = 16)
    {
        $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
        $charactersLength = strlen($characters);
        $randomString = '';
        for ($i = 0; $i < $length; $i++) {
            $randomString .= $characters[rand(0, $charactersLength - 1)];
        }
        return $randomString;
    }
}
