How to use one socket in different js files on the client?

Question

JavaScript

There is a js file in which the following is connected in the closure:

var socket = io("http://localhost/socket"); //путь условный

There is a second js file that is sent only under a certain condition (as it should be), but there I would also like to use the socket library so as not to transfer via ajax, because it is not known how many times to transfer data (from 0 to infinity).
Do not write there again
var socket = io("http://localhost/socket");:)

Answer 1

Well, check if there is a socket , and if it is, send through it.
Declare it globally in general.

Answer 2

the very moment where you can use global variables or your global functions that give access to variables