PHP: How to generate a random, unique, alphanumeric string for use in a secret link?

Question

How would it be possible to generate a random, unique string using numbers and letters for use in a verify link? Like when you create an account on a website, and it sends y

Answer 1

This is a simple function that allows you to generate random strings containing Letters and Numbers (alphanumeric). You can also limit the string length. These random strings can be used for various purposes, including: Referral Code, Promotional Code, Coupon Code. Function relies on following PHP functions: base_convert, sha1, uniqid, mt_rand

function random_code($length)
{
  return substr(base_convert(sha1(uniqid(mt_rand())), 16, 36), 0, $length);
}

echo random_code(6);

/*sample output
* a7d9e8
* 3klo93
*/