odd syntax question angular.js/javascript

Hi Ryan,

This syntax is perfectly valid and is quite common in JavaScript since we've been using it everywhere and not just in AngularJS, in the above code all that's happening is $routeProvider is returning a new object with methods assigned to it in which we're calling using when and otherwise.

See the below example which works the same way only at the end I'm returning a properties value instead of calling another method.

function Test() {
    this.something = 'test';
}

Test.prototype.somethingElse = function() {
    return this;
};

Test.prototype.useless = function() {
    return this;
};

var test = new Test();
alert(test.somethingElse().useless().something);

So again, all I'm doing is chaining methods together by returning the instance of the object via this in the methods allowing me to request the property something because I returned the instance of the object in both somethingElse and useless.

If I didn't return this in the methods I would have got an error similar to the below.

Cannot read property 'something' of undefined

What this is saying is that because we didn't return this we now no longer have access to the object's instance which in-turn kills the chaining we had earlier, however. In AngularJS it's recommend you follow this chaining technique which they do by using an object called a Promise, what a promise allows you to do is execute code asynchronously avoiding un-needed slow downs which can be a big problem if you have a lot of JavaScript running on your page which when using AngularJS will be the case.

Hopefully that didn't zip over your head too much.