Falsy¶
A falsy value is a value that evaluate to false, when cast to a boolean. It includes false, obviously, but also other values such as 0, '' (empty string), or [] (empty array).
The contrary to falsy is truthy.
There are some values which are difficult to guess, as is illustrated below.
<?php
var_dump((bool) 0); // false
var_dump((bool) ''); // false
var_dump((bool) '0'); // false
var_dump((bool) '00'); // true
var_dump((bool) []); // false
var_dump((bool) [null]); // true
var_dump((bool) null); // false
?>
