PHP strcasecmp with empty string equals true?

Basically I have the code:

echo strcasecmp('hello', ' ') ? 'true' : 'false';

I don't quite understand, I'm expecting the result here to be false and not true because the string aren't equal...

Is there another better way to开发者_Go百科 compare strings in a case INSENSITIVE way?

From http://php.net/manual/en/function.strcasecmp.php

int strcasecmp ( string $str1 , string $str2 )

Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.

You need to do it like

echo strcasecmp('hello', ' ') == 0 ? 'true' : 'false';

This should be

echo (strcasecmp('hello', ' ') === 0) ? 'true' : 'false';

The strcasecmp returns 0 if both strings are equal.

http://uk3.php.net/strcasecmp

You're misinterpreting the results. What strcasecmp returns, according to the docs is a number not equal to zero if the strings are unequal, and zero if they are equal. As you know, in PHP zero corresponds to false and non-zero corresponds to true. A proper version of your test is thus

echo (strcasecmp('hello', ' ') === 0) ? 'true' : 'false';

or, alternatively,

echo strcasecmp('hello', ' ') ? 'false' : 'true';

of which I prefer the first one, being more verbose and not containing any implicit type conversions to booleans.