php overload equals-operator
Here's a neat little trick I recently found out:
class Foo { public $a; public $b; public function __toString() { return (string)$this->a; } public function __construct($a, $b) { $this->a = $a; $this->b = $b; }}$a = new Foo(1, 'a');$b = new Foo(2, 'b');$c = new Foo(3, 'c');$d = new Foo(2, 'd');$array = array($a, $b);$key = array_search($d, $array); // false$key = array_search((string)$c, $array); // false$key = array_search((string)$d, $array); // 1This also works:
$is_equal = ((string)$d == $b); // trueWhen passed a string $needle, array_search will try to cast the objects contained in $haystack to string to compare them, by calling the __toString magic method if it exists, which in this case returns Foo::$a.