Can you pass more parameters than a function expects?

问题

If you have two classes extending the same base class, and need to make one of them override a function to take an additional parameter. Is it okay to always pass the additional parameter when calling the function on either class?

A bit of pseudo-code to help demonstrate...

If we have the 3 classes and functions

• foo::doSomething()
• foo_subclass_one::doSomething()
• foo_subclass_two::doSomething($input)

And I have an instance of one of these three, can I call $instance.doSomething($input)

I -think- what happens is that foo and foo_subclass_one would just ignore the additional parameter and foo_subclass_two would make use of it. Is this correct? Is there a better way I can do this if I have a lot of subclasses and really want to avoid touching 10+ files?

Thanks!

回答1:

Yes you can. Gather them with func_get_args()

回答2:

There are two ways to do this:

Extend the methods to use default parameters:

public function doSomething($input=null) {}

Note that you'll need to do this for all instances, even if it isn't used.

In this case, you may want to use the arguments array of the method:

public function doSomething() {
  $args = func_get_args();
  if (isset($args[0])) { $this->doSomethingElse();
}

来源：https://stackoverflow.com/questions/6051309/can-you-pass-more-parameters-than-a-function-expects