Checking to see if a string contains any characters

Question

I would like to check and see if a given string contains any characters or if it is just all white space. How can I do this?

I have tried:

$search_term= " ";

if (preg_match('/ /',$search_term)) {
    // do this
}

But this affects search terms like this as well:

$search_term= "Mark Zuckerburg";

I only want a condition that checks for all white space and with no characters.

Thanks!

trim it. if the length of the trimmed string is 0 then it's of all white spaces. has some other characters otherwise :) — Fallen, Jul 09 '13 at 19:40
possible duplicate of [How to check if there are only spaces in string in PHP?](http://stackoverflow.com/questions/1754393/how-to-check-if-there-are-only-spaces-in-string-in-php) — Felix Kling, Jul 09 '13 at 19:46

Yotam Omer · Answer 1 · 2013-07-09T20:07:38.237

3

Use trim():

if(trim($search_term) == ''){
    //empty or white space only string
    echo 'Search term is empty';
}

trim() will cut whitespace from both start and end of a string - so if the string contains only whitespace trimming it will return empty string.

edited Jul 09 '13 at 20:07

answered Jul 09 '13 at 19:40

Yotam Omer

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score 3 · Answer 2 · answered Jul 09 '13 at 19:41

ctype_space does this.

$search_term = " ";

if (ctype_space($search_term)) {
    // do this
}

The reason your regular expression doesn’t work is that it’s not anchored anywhere, so it searches everywhere. The right regular expression would probably be ^\s+$.

The difference between ctype_space and trim is that ctype_space returns false for an empty string. Use whatever’s appropriate. (Or ctype_space($search_term) || $search_term === ''…)

Checking to see if a string contains any characters

2 Answers2