Question

Write a php program that checks the elements of a string array named $passwords. use regular expressions to test whether each element is a strong password. for this exercise, a strong password must have at least one number, one lowercase letter, one uppercase letter, no spaces, and at least one character that is not a letter or number. (hint: use the [^0-9a-za-z] character class.) th e string should also be between 8 and 16 characters long.

Answer 1

<?php

function pass_strong($candidate) {

   if (!preg_match_all('$\S*(?=\S{8,})(?=\S*[a-z])(?=\S*[A-Z])(?=\S*[\d])(?=\S [\W])\S*$', $candidate))

       return FALSE;

   return TRUE;

}

/*

   Explaining

   $\S*(?=\S{8,})(?=\S*[a-z])(?=\S*[A-Z])(?=\S*[\d])(?=\S*[\W])\S*$

   $ = string beginning

   \S* = characters set

   (?=\S{8,}) =  with length atleast 8

   (?=\S*[a-z]) = with at least 1 letter that is lowercase

   (?=\S*[A-Z]) = with at least 1 letter that is uppercase

   (?=\S*[\d]) = with at least 1 number

   (?=\S*[\W]) = with at least 1 special character

   $ = string end

*/

$Passwords = 'password01';

if(pass_strong($Passwords))

   echo "$Passwords is a strong password
";

else echo "$Passwords is NOT a strong password
";

?>