PHP is_callable() function

Author：Eve Cole Update Time：2024-12-29 13:24:01

The is_callable() function is used to detect whether the function is callable in the current environment.

The is_callable() function verifies whether the contents of a variable can be called as a function. This can check for a variable containing a valid function name, or an array containing a correctly encoded object and function name.

PHP version requirements: PHP 4 >= 4.0.6, PHP 5, PHP 7

grammar

 bool is_callable ( callable $name [, bool $syntax_only = false [, string &$callable_name ]] )

Parameter description:

$name: The callback function to check.

$syntax_only: If set to TRUE, this function only verifies that name may be a function or method. It simply rejects non-characters, or does not contain a valid structure that can be used in the callback function. Valid should contain two elements, the first is an object or character, and the second element is a character.

$callable_name: Accepts "callable_name".

return value

Returns TRUE if name is callable, otherwise returns FALSE. .

Example

<?php // Check whether the variable is a callable function function someFunction ( ) { } $functionVariable = ' someFunction ' ; var_dump ( is_callable ( $functionVariable , false , $callable_name ) ) ; // bool(true) echo $callable_name , " n " ; // someFunction // // The array contains methods // class someClass { function someMethod ( ) { } } $anObject = new someClass ( ) ; $methodVariable = array ( $anObject , ' someMethod ' ) ; var_dump ( is_callable ( $methodVariable , true , $callable_name ) ) ; // bool(true) echo $callable_name , " n " ; // someClass::someMethod ?>

The output is:

 bool(true)someFunctionbool(true)someClass::someMethod