PHP - is_callable() Function
Definition and Usage
The function is_callable() checks whether contents of a variable can be called as a function.
Syntax
bool is_callable ( mixed $value , bool $syntax_only = false , string &$callable_name = null )
Parameters
| Sr.No |
Parameter & Description |
| 1 |
value
Mandatory. The value to be verified
|
| 2 |
syntax_only
Optional. If set to true the function only verifies that value might be a function or method. It will only reject simple variables that are not strings, or an array that does not have a valid structure to be used as a callback. The valid ones are supposed to have only 2 entries, the first of which is an object or a string, and the second a string.
|
| 3 |
callable_name
Optional. Returns a callable name (only for classes)
|
Return Values
This function returns a boolean type value. Returns true if value is callable, false otherwise.
Dependencies
PHP 4.0.6 and above
Example
Following example demonstrates how to check a variable to see if it can be called as a function −
<?php
function testFunction(){
}
$functionVariable = 'testFunction';
var_dump(is_callable($functionVariable, false, $callable_name)); // bool(true)
echo $callable_name. "<br>"; // testFunction
// using only-one parameter
var_dump(is_callable($functionVariable));
?>
Output
This will produce following result −
bool(true) testFunction
bool(true)
php_variable_handling_functions.htm
