Boolean
A boolean is a value that is either true or false.
PHP’s boolean are constants. They may be prefixed by \, and are case-insensitive. They can’t be redefined in any namespace.
There are operators to convert any data to a boolean, and operators to combine boolean together. There are also bit operators, which process integers as a field of boolean.
Booleans have a related scalar type: bool. There is also a special false type.
<?php
$a = True;
$b = \FALSE;
?>