Example
Callables are anything which can be called as a callback. Things that can be termed a "callback" are as follows:
-
Anonymous functions
-
Standard PHP functions (note: not language constructs)
-
Static Classes
-
non-static Classes (using an alternate syntax)
-
Specific Object/Class Methods
-
Objects themselves, as long as the object is found in key
0of an arrayExample Of referencing an object as an array element:
$obj = new MyClass();
call_user_func([$obj, 'myCallbackMethod']);
Callbacks can be denoted by callable type hint as of PHP 5.4.
$callable = function () {
return 'value';
};
function call_something(callable $fn) {
call_user_func($fn);
}
call_something($callable);
