Possible Duplicate:
If string only contains spaces?
I do not want to change a string nor do I want to check if it contains white space. I want to check if the entire string is ONLY white space. What the best way to do that?
views:
180answers:
4
+11
A:
since trim returns a string with whitespace removed, use that to check
if (trim($str) == '')
{
//string is only whitespace
}
MANCHUCK
2010-06-07 19:08:38
Hmm, indeed, faster then the preg_* route..
Wrikken
2010-06-07 19:09:49
+1 for a non regex solution. Not that there is anything wrong with regex.
Neil Aitken
2010-06-07 19:10:12
Just remember that trim will turn anything you pass into it into a string. i.e (trim(false) == '') will return true, which may fall outside the original poster's requirements (but it most likely fine)
Alan Storm
2010-06-07 19:25:48
+2
A:
preg_match('/^\s*$/',$string)
change * to + if empty is not allowed
Wrikken
2010-06-07 19:08:44
@John, as said, whitespace, perhaps your confusing the character class ^ ([^p] = anything not 'p') with '^p' (= string has to start with p)
Wrikken
2010-06-07 19:25:24
I'm voting down only because you should avoid regex only when needed. For something simple as this, build in PHP functions are the way to go
MANCHUCK
2010-06-07 19:48:40
@Wrikken, yes thanks. I have never used the \s char, plus I think regex is much easier to write than to read.
John Isaacks
2010-06-07 20:15:29
Wrikken
2010-06-07 21:26:25
+4
A:
if( trim($str) == "" )
// the string is only whitespace
This should do the trick.
svens
2010-06-07 19:08:56
+10
A:
This will be the fastest way:
$str = ' ';
if (ctype_space($str)) {
}
Returns false on empty string because empty is not white-space. If you need to include an empty string, you can add || $str == '' This will still result in faster execution than regex or trim.
webbiedave
2010-06-07 19:16:42
Wow, I didn't imagine it could get much simpler than the trim, but I guess it can. +1 for a function I've never seen or used.
epalla
2010-06-07 19:21:11