How to define a new global object in javascript

Question

Hi It is good practice to create one unique global object that wrap the functions and properties inside this object.I look up a lot of sample code and see code like this

if(!myglobalObject) myglobalObject ={};

However , this code does not work ,I got an error saying ReferenceError: myglobalObject is not defined Can anyone shed some light on why I got the error?

Answer 1

if (myglobalObject == null) myglobalObject = {}

Answer 2

if (window['myglobalObject'] === undefined) window.myglobalObject = {};

If you don't want to expose your object from context you can do smth like this:

var myglobalObject = myglobalObject || {};

Answer 3

if (typeof myglobalObject === 'undefined') var myglobalObject = {};

Answer 4

To avoid errors in ECMAScript 5 strict mode, you need to use var to define all variables:

if (typeof myglobalObject == "undefined") {
    var myglobalObject = {};
}

The other alternative is to assign a property to the global object:

// The following line gets you a global object in any ECMAScript environment.
// In browsers, you could just use window.
var globalObj = (function() { return this; })();
if (typeof globalObj.myglobalObject == "undefined") {
    globalObj.myglobalObject = {};
}