is_callable

Name:is_callable

Category:Variable processing

Programming Language:php

One-line Description:Check whether the content of the variable can be called as a function.

Definition and usage

is_callable() function checks whether the content of a variable can be called as a function.

If the variable is callable, the function returns true (1), otherwise false / nothing is returned.

Example

Check whether the content of a variable can be called as a function:

 <?php
function test1 ( ) {
}

echo "test1 is callable: " . is_callable ( "test1" ) ;
echo "<br>" ;
echo "test2 is callable: " . is_callable ( "test2" ) ;
?>

Try it yourself

grammar

 is_callable ( variable , syntax_only , name ) ;

parameter	describe
variable	Required. Specifies the variable to check.
syntax_only	Optional. If set to TRUE, the function only verifies whether the variable is a function or method. It will reject variables that are not strings, or arrays that have no valid structures to use as callbacks. Default is false.
name	Optional. Returns a "callable name" (for classes only).

parameter

describe

variable

Required. Specifies the variable to check.

syntax_only

Optional. If set to TRUE, the function only verifies whether the variable is a function or method.

It will reject variables that are not strings, or arrays that have no valid structures to use as callbacks.

Default is false.

name

Optional. Returns a "callable name" (for classes only).