No more than 1 space next to each other

[Kryptix]

I'm using this to check username's are valid (letters, numbers and spaces):

 

if (!preg_match("/^[a-zA-Z0-9 ]+$/", $username))

 

However, people can use names like "Hello    4" (5 spaces in a row). How would I eliminate this?

 

Is it best to just replace the 5 spaces with 1 or would that confuse users?

 

Is it best to just throw an error up?

 

Can someone change the regex above to fix it or is it more complicated than that?

[ktroztafy]

Try :

 

preg_replace('/( )+/', ' ', $username);

 

to remove all white-space, then use your own code to check the $username

[jcbones]

So you want to allow 1 space, but no more?  The above code given will remove ALL spaces.

 

1 space but no more is:

preg_replace('~\s\s+~','',$username);

[melloorr]

trim($username);

[Pikachu2000]

trim() only removes leading and trailing whitespace, not whitespace between other characters.