如何在javascript中定义新的全局对象

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

Answer 2

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, so long as it runs in the global scope. In browsers,
// you could just use window.
var globalObj = this;
if (typeof globalObj.myglobalObject == "undefined") {
    globalObj.myglobalObject = {};
}

Answer 3

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

如果你不想从上下文中公开你的对象，你可以像这样做：

var myglobalObject = myglobalObject || {};