Dual or triple (or even multiple) comparison in JavaScript -

Almighty Gurus, please tell me, I want to know that the comparison can be SM. The set of variables in the row, like this:

  x  

Or do I need to do it in two steps?

  (x  = z)  

In JavaScript, you should compare this type of Should in two stages

Python is the only widely used language that I know that forms are allowed before (please comment if I am wrong).