Still confused about JavaScript's 'this'.
Posted
by Nick Lowman
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Published on 2010-04-28T11:09:01Z
Indexed on
2010/04/28
11:13 UTC
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JavaScript
I've been reading through quite a few articles on the 'this' keyword when using JavaScript objects and I'm still somewhat confused. I'm quite happy writing object orientated Javascript and I get around the 'this' issue by referring the full object path but I don't like the fact I still find 'this' confusing.
I found a good answer here which helped me but I'm still not 100% sure. So, onto the example. The following script is linked from test.html with <script src="js/test.js"></script>
if (!nick) {
var nick = {};
}
nick.lowman = function(){
var helloA = 'Hello A';
console.log('1.',this, this.helloA);
var init = function(){
var helloB = 'Hello B';
console.log('2.',this, this.helloB);
}
return {
init: init
}
}();
nick.lowman.init();
What kind of expected to see was
1. Object {} nick.lowman, 'Hello A'
2. Object {} init, 'Hello B'
But what I get is this?
1. Window test.html, undefined
2. Object {} init, undefined
I think I understand some of what's happening there but I would mind if someone out there explains it to me.
Also, I'm not entirely sure why the first 'console.log' is being called at all? If I remove the call to the init function //nick.lowman.init()
firebug still outputs 1. Window test.html, undefined
. Why is that? Why does nick.lowman() get called by the window object when the html page loads?
Many thanks
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