How to declare abstract method in non-abstract class in PHP?

class absclass {
    abstract public function fuc();
}

reports:

PHP Fatal error: Class absclass

contains 1 abstract method and must
therefore be declared abstract or
implement the remaining methods
(absclass::fuc)

I want to know what it means by implement the remaining methods,how?

Answer

I presume that remaining methods actually refers to the abstract methods you're trying to define (in this case, fuc()), since the non-abstract methods that might exist are okay anyway. It's probably an error message that could use a better wording: where it says remaining it should say abstract.

The fix is pretty straightforward (that part of the error message is fine): you need to change this:

abstract public function fuc();

... into a proper implementation:

public function fuc(){
    // Code comes here
}

... or, alternatively and depending your needs, make the whole class abstract:

abstract class absclass {
    abstract public function fuc();
}