Question

RT

function 1 :

$class->$func()

function 2:

//Simple callback
call_user_func($func)
//Static class method call
call_user_func(array($class,$func))
//Object method call
$class = new MyClass();
call_user_func(array($class, $func));

Is there a difference? I want to see the sourcecode(https://github.com/php/php-src) should we do?

Answer 1

call_user_func_array is very slow performance-wise, that’s why in many cases you want to go with explicit method call. But, sometimes you want to pass arbitrary number of arguments passed as an array, e.g.

public function __call($name, $args) {
    $nargs = sizeof($args);
    if ($nargs == 0) {
        $this->$name();
    }
    elseif ($nargs == 1) { 
        $this->$name($args[0]);
    }
    elseif ($nargs == 2) { 
        $this->$name($args[0], $args[1]);
    }
    #...
    // you obviously can't go through $nargs = 0..10000000, 
    // so at some point as a last resort you use call_user_func_array
    else { 
        call_user_func_array(array($this,$name), $args);
    }
}

I’d go with checking $nargs up to 5 (it’s usually unlikely that a function in PHP accepts more than 5 arguments, so in most cases we will call a method directly without using call_user_func_array which is good for performance)

The result of $class->method($arg) is the same as call_user_func_array(array($class,'method'), array($arg)), but the first one is faster.