What does this actually do?

[TeddyKiller]

Small code. Little reply.

$alpha_num = str_replace(" ", "", $username);
if (!ctype_alnum($alpha_num)) :
    return 2;
endif;

 

What does it do?

 

Thanks

[Lamez]

I think it checks to see if the string contains any letters or digits. If it does not, it returns 2

[TeddyKiller]

Isn't $alpha_num = str_replace(" ", "", $username); equivalent to $alpha_num = trim($username);

So if ctype_alnum() checks if the string is alphabetic and/or numeric... is it an old function? Has it been deprecated? Never seen it used before.

[kenrbnsn]

No, it's not the same as using trim. The str_replace removes all spaces from the string, not just the ones before/after like trim().

 

Ken

[Lamez]

Not sure on the trim function, but the first line takes out the spaces of the string and mashes it all into one for easier checking.

 

See the manual for the second function: http://php.net/manual/en/function.ctype-alnum.php

 

I've used it before, can't remember for what.