PHP - Can you assign a member function to a variable? [duplicate] - php

Question

This question already has answers here:
php call class function by string name
(6 answers)
Closed 8 years ago.
In PHP5, variables can be evaluated as functions1 such as:
function myFunc() {
echo "whatever";
}
$callableFunction = 'myFunc';
$callableFunction(); // executes myFunc()
Is there any syntax for assigning object member functions to a variable such as:
class MyClass {
function someCall() {
echo "yay";
}
}
$class = new MyClass();
// what I would like:
$assignedFunction = $class->someCall; // but I tried and it returns an error
$memberFunc = 'someCall';
$class->$memberFunc(); // I know this is valid, but I want a single variable to be able to be used to call different functions - I don't want to have to know whether it is part of a class or not.
// my current implementation because I don't know how to do it with anonymous functions:
$assignedFunction = function() { return $class->someCall(); } // <- seems lengthy; would be more efficient if I can just assign $class->someCall to the variable somehow?
$assignedFunction(); // I would like this to execute $class->someCall()

Answer 1

There is a way, but for php 5.4 and above...
class MyClass {
function someCall() {
echo "yay";
}
}
$obj = new Myclass();
$ref = array($obj, 'someCall');
$ref();
Hm.. actually it works for static too, just use the reference by name..
class MyClass {
static function someCall2() {
echo "yay2";
}
}
$ref = array('MyClass', 'someCall2');
$ref();
And for nonstatic this notation works as well. It creates a temporary instance of the class. So, this is what you need, only you need php 5.4 and above )

Answer 2

The PHP 5.4 solution above is good. If you need PHP 5.3, I don't think you can do much better than the anonymous function approach, but you could wrap that into a function that acts very similar to the PHP 5.4 method:
function buildCallable($obj, $function)
{
return function () use ($obj, $function) {
$args = func_get_args();
return call_user_func_array(array($obj, $function), $args);
};
}
//example
class MyClass
{
public function add($x, $y)
{
return $x + $y;
}
public static function multiply($x, $y)
{
return $x * $y;
}
}
//non-static methods
$callable = buildCallable(new MyClass(), 'add');
echo $callable(32, 10);
//static methods
$callable = buildCallable('MyClass', 'multiply');
echo $callable(21, 2);
This should work for any number of arguments to any (publicly visible) method.