#php Generate a random code with pre-defined length and characters PHP

random_codes.php

<?php

echo random_code(6); //E4QGR9
echo PHP_EOL;

echo random_digits(6); //610470
echo PHP_EOL;

echo random_chars(6); //XBRBDH
echo PHP_EOL;

echo random_code(6, 'ABC123'); //221B21

function random_digits($length) {
   return random_code($length, join(range(0,9)));
}

function random_chars($length) {
   return random_code($length, join(range('A', 'Z')));
}

//modified from https://stackoverflow.com/a/13169091
function random_code(
    $length, 
    $chars = 'ABCDEFGHIJKLMNPQRSTUVWXYZ123456789'
) {
  $result = '';
  $char_length = strlen($chars);

  for ($i = 0; $i < $length; $i++) {
    $randomIndex = random_int(0, $char_length - 1);
    $result .= $chars[$randomIndex];
  }

  return $result;
}