The is_bool Function
The is_bool function checks whether the passed value is
of boolean type (true or false). The function returns true,
if the value is boolean, and false otherwise.
The function accepts one parameter - the value to check.
Syntax
is_bool(mixed $value): bool
Example
Let's check several values for belonging to the boolean type:
<?php
$res1 = is_true;
$res2 = is_false;
$res3 = is_bool(1);
$res4 = is_bool('true');
var_dump($res1, $res2, $res3, $res4);
?>
Code execution result:
true
true
false
false
Example
Let's check variables of different types:
<?php
$boolVar = false;
$intVar = 0;
$strVar = 'false';
var_dump(
is_bool($boolVar),
is_bool($intVar),
is_bool($strVar)
);
?>
Code execution result:
true
false
false
