What is the advantage of initializing multiple javascript variables with the same var keyword?

Question

When I read javascript code that is clean and written by people who are obviously very good at it, I often see this pattern

var x = some.initialization.metho         


        

Answer 1

Other than the on-wire size, it probably helps interpreter performance as well. From Professional Java Script for Web Developers:

A single statement can complete multiple operations faster than multiple statements each performing a single operation. The task, then, is to seek out statements that can be combined in order to decrease the execution time of the overall script.

It went on to recommend declaring variables in a single line.