This article should have like a [satire] or something attached. It's not super obvious until you get a little ways into this that this is a joke article and these are not real operators. Even then, it might not be obvious if you're not a PHP developer.
The description is clearly a joke, although they are real operators (or strange uses of other operators). For example, -=- is subtraction assignment operator and negative operator together, which results in addition. However, the description of +-0-+ is wrong; it subtracts and does not add (this is what I thought, so I tried it to see and I am right and the article there is wrong).