Checking for empty arrays: count vs empty

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This question on 'How to tell if a PHP array is empty' had me thinking of this question

Is there a reason that count should be used instead of empty when determining if an array is empty or not?

My personal thought would be if the 2 are equivalent for the case of empty arrays you should use empty because it gives a boolean answer to a boolean question. From the question linked above, it seems that count($var) == 0 is the popular method. To me, while technically correct, makes no sense. E.g. Q: $var, are you empty? A: 7. Hmmm...

Is there a reason I should use count == 0 instead or just a matter of personal taste?

As pointed out by others in comments for a now deleted answer, count will have performance impacts for large arrays because it will have to count all elements, whereas empty can stop as soon as it knows it isn't empty. So, if they give the same results in this case, but count is potentially inefficient, why would we ever use count($var) == 0?

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Is there a reason that count should be used instead of empty when determining if an array is empty or not?

There is, when you need to do something on non-empty array knowing it's size:

if( 0 < ( $cnt = count($array) ) )
{
 echo "Your array size is: $cnt";
}
else
 echo "Too bad, your array is empty :(";

But I wouldn't recommend using count, unless you are 100% sure, that what you are counting is an array. Lately I have been debugging code, where on error function was returning FALSE instead of empty array, and what I discovered was:

var_dump(count(FALSE));

output:

int 1

So since then I am using empty or if(array() === $array) to be sure that I have array that is empty.

answered 2010-02-07T09:16:36.250

Checking for empty arrays: count vs empty

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