PHP's variable type leniency

Question

The most recent comment on PHP\'s in_array() help page (http://uk.php.net/manual/en/function.in-array.php#106319) states that some unusual results occur as a re

Answer 1

PHP treating arrays as primitive values is a constant source of pain as they can be very complex data structures, it doesn't make any sense. For example, if you assign array to something, and then modify the array, the original isn't modified, instead it is copied.

 NULL
);



var_dump( array() == NULL ); //True :(
var_dump( in_array( array(), $arr ) ); //True, wtf? It's because apparently array() == NULL
var_dump( in_array( new stdClass, $arr ) ); //False, thank god

?>

Also, 'egg' is not a value in the array, it's a key, so of course it's surprising that it would return true. This kind of behavior is not ok in any other language I know about, so it will trip over many people who don't know php quirks inside out.

Even a simple rule that an empty string is falsy, is violated in php:

if( "0" ) {
echo "hello"; //not executed
}

"0" is a non-empty string by any conceivable definition, yet it is a falsy value.