[RESOLVED] Array help needed

[middleman666]

Hey people,

I'm not quite sure how to do this or if I'm going about it the right way so thought I'd ask for some guidence..

What I want to do is allow users to create a username that can use letters, numbers and underscores (_).

So what I started off doing was trying to create an array with all other characters in so that these would be the 'invalid' characters. Then I was just going to say IF username has a character from the array then show an error.

This is what I started doing, but this array shows errors as I'm not sure what characters I should be telling the code to ignore using .

//Create array of invalid characters
$invalid = array(' ','¬','¦','`','!',''','£','$','%','^','&','*','(',')','-','+','=','~','#','{','}','[',']','|','\','\:','\;','\@','\'','<',',','\.','?','/');

Can anyone help me with my array or let me know a better was of doing this?

I did look into preg_match but I didn't understand the patterns to use.

Thanks

[Installer]

Wouldn't it be easier to check against an array of characters that are valid?

$valid = array_merge(range('a', 'z'), range('A', 'Z'), range('0', '9'), array('_'));

[leatherback]

or..

if(! eregi("[a-z0-9_]", $string))
{
// something wrong
}

[middleman666]

leatherback wrote:

or..

if(! eregi("[a-z0-9_]", $string))
{
// something wrong
}

Thanks for your help, I think I'll go with this option 🙂

[middleman666]

Sorry, I seem to be having a problem...

When I enter just % it will say its an invalid character and when I enter Letters and or numbers it says its fine, but when I enter something like LEtters%09 it still validates as being fine.

How can I stop this happening?

Thanks