在object方法中返回一个值还是在object方法中设置值？ PHP

Question

I can write classes which do the exact same thing two different ways;

class Simple {

    private $var;

    public function __construct() {

        $this->var = $this->setVar();
    }

    private function setVar() {

        return true;
    }
}

Or

 class Simple {

    private $var;

    public function __construct() {

        $this->setVar();
    }

    private function setVar() {

        $this->var = true;
    }
}

When would I use one over the other? I have seen many different php applications use the two different types. But there seems no general guideline to follow, or does it even matter for that fact?

Answer 1

Setters should set, not return. This should need no more explanation.