Entry

Can I make an assignment to $this in a class method?

How can I reset or clear the value of an object?

Jun 30th, 1999 20:20
Nathan Wallace, Ben Udall, Mark, Steve Dicks

The complete '$this' pointer should be considered read-only in methods
(you are attempting to overwrite yourself, never a good thing). If you
tried this is any other language it is unlikely to work either.
Here is an example where the clear() method will cause problems in PHP:
    class Ob {
        var $i = 1;
        function set_i ($a) { $this->i = $a; }
        function clear () { $this = new Ob; }
    }
If you want to clear an object, or any case where you might be tempted
to assign a value to the $this pointer, you should just set the values
of the variables contained in the $this object.
So the correct solution for the bad class example above is:
    class Ob {
        var $i = 1;
        function set_i ($a) { $this->i = $a; }
        function clear () { $this->i = 1 }
    }