How to get the global variable of an element to avoid being polluted?

Question

var ele=document.getElementById('btn'); When writing native js, you need to obtain a large number of page elements. Now that there are too many global variables, how do you avoid being polluted?

phpcn_u1582 · Answer

Open namespace:
var name={};
name.common={};
name.fx={};
name.site={};
name.common.ele1= document.getElementById('btn' );
neme.fx.ele1= document.getElementById('btn2');

淡淡烟草味 · Answer

Wrap it in IIFE and don’t put it globally.

大家讲道理 · Answer

Same upstairs, wrap one floor with IIFE

(function () {
    var foo = '...';
    var baar = '...';
})();

黄舟 · Answer

Modular. requirejs/webpack/ES6 modules, variables are all private to the module.