PHP strings Generating a Random String

PHP Strings

Generating a Random String

Problem

You want to generate a random string.


Solution

            function str_rand($length = 32,
                      $characters = ↵
            '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') {
            if (!is_int($length) || $length < 0) {
                      return false;
            }
                     $characters_length = strlen($characters) - 1;
            $string = '';

            for ($i = $length; $i > 0; $i--) {

            $string .= $characters[mt_rand(0, $characters_length)];

            }

                      return $string;

            }

Discussion

PHP has native functions for generating random numbers, but nothing for random

strings. The str_rand() function returns a 32-character string constructed from letters

and numbers. Pass in an integer to change the length of the returned string. To use an alternative set of characters, pass them as a string as the second argument. 

For example, to get a 16-digit Morse Code:

           print str_rand(16, '.-');