checking a password for upper lower numbers and symbols

Question

I am using the below script to check my passwords for length, uppercase, lowercase and numbers.

How could I change it to make it check FOR symbols instead of against symbols?

<?php
    $password = 'afsd323A';
    if( 
        //I want to change this first line so that I am also checking for at least 1 symbol.
            ctype_alnum($password) // numbers & digits only 
        && strlen($password)>6 // at least 7 chars 
        && strlen($password)<21 // at most 20 chars 
        && preg_match('`[A-Z]`',$password) // at least one upper case 
        && preg_match('`[a-z]`',$password) // at least one lower case 
        && preg_match('`[0-9]`',$password) // at least one digit 
        )
    { 
        echo 'valid';
    }
    else
    { 
        echo 'not valid';// not valid 
    }     
?> 

Solution 1

your desired regex is below

   $pattern = ' ^.*(?=.{7,})(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).*$ ';
   preg_match($pattern,$password);

DEMO

Solution 2

Either you determine a list of valid symbols:

preg_match('`[\$\*\.,+\[email protected]]`',$password)

or you can look for anything that isn't alnum:

preg_match('`[^0-9a-zA-Z]`',$password)

Comments

[Craig White]

To check if it contains non-alphanumeric characters try this regular expressions: if(preg_match('/[^a-zA-Z0-9]/', $password) echo('Password contains non-alphanumeric characters');

[Jacob]

Except that OP wants the password to contain at least one of each. At least one upper, one lower, one digit, and one symbol.

[diEcho]

Please try to google... here it is Reference

[Dmitrij Golubev]

I optimized a bit ((?=.*[A-Z])(?=.*[a-z])(?=.*\d).{7,21}) - 27 steps ; your - in 50 steps;

[diEcho]

@Dmitrij how do u find the steps?? any website?? please refer

[Dmitrij Golubev]

I am using RegexBuddy (powerfull and chip tool). Example of debugging you can find here

[Nico Haase]

Please add some explanation to your answer such that others can learn from it