array_search() returns 1 if $needle is 0

Question

This is weird thing I found with array_search();

$test = array(
  1 => 'first', 
  2 => 'second'
);

Now if the needle to be searched comes as 0 For eg:

$val = 0;
$key = array_search($val, $test);

Now $key is returned as 1 (the first key).

Does anyone know how to deal with such behaviour and return false for this check ? Is it documented anywhere ? I've searched but not found even on SO.

Thanks!

Answer 1

This is not a bug, but how PHP handles comparisons. As $val is an integer, PHP will convert your strings to integers for the comparison. Converting 'first' to an integer will give you 0, and so the comparison is 0 == 0, which is obviously true. That's why it returns the first result.