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(PHP 4 >= 4.0.6, PHP 5)

is_callable — Verify that the contents of a variable can be called as a function


bool is_callable ( mixed $var [, bool $syntax_only [, string &$callable_name ]] )

Verify that the contents of a variable can be called as a function. This can check that a simple variable contains the name of a valid function, or that an array contains a properly encoded object and function name.



Can be either the name of a function stored in a string variable, or an object and the name of a method within the object, like this:

array($SomeObject, 'MethodName')


If set to TRUE the function only verifies that var 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.


Receives the "callable name". In the example below it is "someClass:someMethod". Note, however, that despite the implication that someClass::SomeMethod() is a callable static method, this is not the case.

Return values

Returns TRUE if var is callable, FALSE otherwise.


Example#1 is_callable() example

//  How to check a variable to see if it can be called
//  as a function.

//  Simple variable containing a function

function someFunction() 

$functionVariable 'someFunction';

var_dump(is_callable($functionVariablefalse$callable_name));  // bool(true)

echo $callable_name"\n";  // someFunction

//  Array containing a method

class someClass {



$anObject = new someClass();

$methodVariable = array($anObject'someMethod');

var_dump(is_callable($methodVariabletrue$callable_name));  //  bool(true)

echo $callable_name"\n";  //  someClass:someMethod