Accessing a Jquery selector as an object property, unexpected outcome

Trying to refer to the object you're defining as this during object instantiation doesn't work like you're expecting it to.

this in your example actually refers to the window object. Some browsers (e.g., Chrome and IE) will attach named DOM nodes to the document and/or window objects, which is why this.testDiv refers to the element with id="testDiv". It just so happens the property name you're trying to access has the same value as the element ID.

To demonstrate what's really going on, try this:

<div id="test"></div>

var myObj = {
    prop1: $('#test'),
    prop2: this.prop1
};

this.prop1 in the context of myObj should be undefined, but window.test may (depending on the browser) refer to the DOM node <div id="test"></div>.

Given your example, you could do your assignment as follows:

var myObj = { prop1: $('#test') };
myObj.prop2 = myObj.prop1;

or

var test = $('#test');
var myObj = {
    prop1: test,
    prop2: test
};