Why can't I overload constructors in PHP?

Question

I know it can't be done, well I hope it can't or my Google skills have failed me.

But my annoyance is beyond that now, I have abandoned all hope of ever being able to overload my constructors in PHP, so what I'd really like to know is why. Is there even a reason for it? Does it create inherently bad code? Is it widely accepted language design to not allow it, or are other languages nicer than PHP?

Answer 1

As far as I know, constructor overloading in PHP is not allowed, simply because the developers of PHP did not include that functionality - this is one of the many complaints about PHP.

I've heard of tricks and workarounds, but true overloading in the OOP sense is missing. Maybe in future versions, it will be included.

Answer 2

You can use variable arguments to produce the same effect. Without strong typing, it doesn't make much sense to add, given default arguments and all of the other "work arounds."

Answer 3

True overloading is indeed unsupported in PHP. As @Pestilence mentioned, you can use variable arguments. Some people just use an Associative Array of various options to overcome this.

Answer 4

I'm really no OOP expert, but as I understand it overloading means the ability of a method to act differently depending in the parameters it receives as input. This is very much possible with PHP, you just don't declare the input types since PHP does not have strong typing, and all the overloading is done at runtime instead of compile time.

Answer 5

You can't overload ANY method in PHP. If you want to be able to instantiate a PHP object while passing several different combinations of parameters, use the factory pattern with a private constructor.

For example:

public MyClass {
    private function __construct() {
    ...
    }

    public static function makeNewWithParameterA($paramA) {
        $obj = new MyClass(); 
        // other initialization
        return $obj;
    }

    public static function makeNewWithParametersBandC($paramB, $paramC) {
        $obj = new MyClass(); 
        // other initialization
        return $obj;
    }
}