Check if the string is just a space?

Question

Possible duplicate:
If the line contains spaces?

I do not want to change the line and do not want to check if it contains a space. I want to check if the whole line is ONLY a space. What is the best way to do this?

Answer 1

This will be the fastest way:

$str = ' '; if (ctype_space($str)) { } 

Returns false on an empty string because empty is not white space. If you need to include an empty string, you can add || $str == '' || $str == '' This will still lead to faster execution than regular expression or trimming.

ctype_space

Answer 2

since trim returns a string with a space removed, use this to check

 if (trim($str) == '') { //string is only whitespace } 

Answer 3

 if( trim($str) == "" ) // the string is only whitespace 

That should do the trick.

Answer 4

preg_match('/^\s*$/',$string)

change * to + if empty is not allowed