The nuance of the switch in javascript: two expressions in swtch (exp, exp2), why?

Question

JavaScript

Dobroden.
I'm parsing slightly shrunk and obfuscated code.
I found a similar construction there:
switch($b = $c, $var) {
Is it equivalent to the expressions:

$b = $c;
switch($var) {

Or does it have some other meaning?

Answer 1

habrahabr.ru/post/116827