validating alphanumeric password

[thecommonthread]

How do check if a string has only lowercase/uppercase letters and has at least one number in it?

 

Thanks!!

[snizkorod]

http://php.net/manual/en/function.ctype-alnum.php

[TOA]

The regex section will have your answer

[.josh]

ctype_alnum by itself only checks that it is an alphanumeric string.  It does not determine whether it has at least one number in it.

 

if (preg_match('~^[a-z0-9]*[0-9][a-z0-9]*$~i',$subject)) {
  // $subject is alphanumeric and contains at least 1 number
} else {
  // failed
}

 

OP: This code will do what you want with one caveat: Technically a string consisting of a single digit like "9" will pass.  If you want to do other things like enforce a minimum/maximum length, be more specific.