I'm fairly new to PHP, and I'm setting up a "members area" for my site following this tutorial. There seems to be a problem with the code near the bottom of the page.
When trying to pick out the invalid characters from a username field, the array $junk is set up.
$junk = array('.' , ',' , '/' , '\' , '`' , ';' , '[' , ']' , '-', '_', '*', '&', '^',
'%', '$', '#', '@', '!', '~', '+', '(', ')', '|', '{', '}', '<', '>', '?', ':', '"', '=');
This block of code returns a syntax error for me.
Now, my first thought was that either the '#' or the '(' and ')' was causing the problem, since they are commonly used in html and php. The error was still returned with them removed.
I am new to php, so it very well could be just some small syntax error I am missing. Any input would be great. Thanks!
EDIT: Also, if there is an easier way of doing this, please let me know!
There is a much easier way to do this, regular expressions. If you want to set up the username to only accept alpha-numeric characters it's,
$user = preg_replace("/[^0-9a-zA-Z]+/", "", $user);
The expression essentially says, replace anything that is not 0-9, a-z, A-Z with "". If you want to allow the "@", "." (period) and "-" and "_" symbols:
$user = preg_replace("/[^0-9a-zA-Z\@\.\-\_]+/", "", $user);
Regular expressions are a very powerful tool. They can be used in most languages, including javascript and PHP. So it is worth taking the time to learn them.
For '\' character you need to write it like
'\\'
The backslash needs to be escaped: '\\'. That's because \' gives you a literal apostrophe, which you couldn't otherwise get inside a singly quoted string.
for a smaller array, make a string and then call str_split to get it as an array of chars.
$junk = str_split('.,/\\`;[]-_*&^%S#@!~+()|{}<>?:"=')
Personally I would have used the chars in the following order
~`!@#$%^&*()-_+={}[]\|;:'",.<>/?
Since that is how they are on my keyboard. But that's just a minor issue. I knows the ' (single quote) is missing from the original string.
Better ways to validate input involve regular expressions.