Question

Possible duplicate of Reference – What does this symbol mean in PHP?

What does it mean when you have something like this $this->_view->id ?

It is within a class (obviously) and I understand the $this. I get how to use one -> to refer to a property or call a method. But what about when there are two -> in one thing?

The fuller code is:

$viewid = ($this->_view) ? $this->_view->id : null;

I’m guessing the overall gist is: Set $viewid to either (1) the value of $this->_view->id or (2) null, depending on whether $this->_view is TRUE or not. But I don’t get the (1) bit.

Also, is it conventional to use an underscore (_view) to show a property or a method?

Thanks.

Answer 1

This means that there is an object stored within an object.

$this->_view refers to an object called $_view within. So within $_view object $this->id would refer to its $id variable.

So calling $this->_view->id calls for variable $id in an object $_view that is stored in your current object (since you said its $this).

Detailed:

class firstClass {
    public $_view;
}
class secondClass{
    public $id=1;
}
$a=new firstClass();
$a->_view=new secondClass();
echo $a->_view->id; // prints 1