Should I use window.variable or var?

Question

We have a lot of setup JS code that defines panels, buttons, etc that will be used in many other JS files.

Typically, we do something like:

grid.js

Answer 1

One nice use of window.variable is that you can check it without having a javascript error. For example, if you have:

if (myVar) {
    //do work
}

and myVar is not defined anywhere on the page, you will get a javascript error. However:

if (window.myVar) {
    //do work
}

gives no error, and works as one would expect.

var myVar = 'test' and window.myVar = 'test' are roughly equivalent.

Aside from that, as other said, you should descend from one global object to avoid polluting the global namespace.