在实例化期间访问类函数

Question

I've done some research and found this SO-Post and this Php Docs...

Now my problem is, it's not working!

My current php version is 5.4.12 which this feature that I'm after is compatible with 5.4. I'm wondering why it's not working?

This is what I'm after and the stuff I've tried so far...

For example, we have a class of:

class MyClass
{
    private $var = "";

    public function __construct()
    {
        // either with or without
        // return $this;
    }

    public static function newObj()
    {
        return new self;
    }

    public function setVar($var)
    {
        $this->var = $var;
    }
}

And I've tried these:

$obj = (new MyClass)->setVar("foo");

// or

$obj = MyClass::newObj()->setVar("foo");

But none work and when I get the $obj value using var_dump, it's just null.

EDIT

I've also tried and placed an echo inside the __construct to see if the class is being initialize, and it is.

Answer 1

As setVar is not returning anything, the left hand site must be null.

$obj = new MyClass();
$obj->setVar("foo");

will work.

Other way, but quite unusual since setters normally do not return anything:

...
public function setVar($var)
{
    $this->var = $var;
    return $this;
}
...

// now this will work:
$obj = (new MyClass)->setVar("foo");

but for me this is obscure code.