The is_callable Function
The is_callable function checks if the passed value can be called as a function.
It returns true if the value is:
- a function name as a string
- an array with an object and a method name
- an object with the
__invokemethod - an anonymous function
Syntax
is_callable(
mixed $value,
bool $syntax_only = false,
string &$callable_name = null
): bool
Example
Checking a regular function:
<?php
function test() {}
$res = is_callable('test');
var_dump($res);
?>
Code execution result:
true
Example
Checking a class method:
<?php
class MyClass {
public function method() {}
}
$obj = new MyClass();
$res = is_callable([$obj, 'method']);
var_dump($res);
?>
Code execution result:
true
Example
Checking a non-existent function:
<?php
$res = is_callable('non_existent_function');
var_dump($res);
?>
Code execution result:
false
Example
Checking an object with __invoke:
<?php
class Invokable {
public function __invoke() {}
}
$obj = new Invokable();
$res = is_callable($obj);
var_dump($res);
?>
Code execution result:
true
See Also
-
the
function_existsfunction,
which checks for the existence of a function -
the
method_existsfunction,
which checks for the existence of a class method
