Javascript How to define multiple variables on a single line?

Question

Reading documentation online, I\'m getting confused how to properly define multiple JavaScript variables on a single line.

If I want to condense the following code,

Answer 1

note you can only do this with Numbers and Strings

you could do...

var a, b, c; a = b = c = 0; //but why?

c++;
// c = 1, b = 0, a = 0;