Function as array value

Question

I can\'t seem to find anything of this, and was wondering if it\'s possible to store a function or function reference as a value for an array element. For e.g.

Answer 1

You can "reference" any function. A function reference is not a reference in the sense of "address in memory" or something. It's merely the name of the function.

 'strlen',
  'class_function' => array('ClassName', 'functionName'),
  'object_method' => array($object, 'methodName'),
  'closure' => function($foo) {
    return $foo;
  },
);

// while this works
$functions['regular']();
// this doesn't
$functions['class_function']();

// to make this work across the board, you'll need either
call_user_func($functions['object_method'], $arg1, $arg2, $arg3);
// or
call_user_func_array($functions['object_method'], array($arg1, $arg2, $arg3));