Class field initialization in typescript

In typescript class, you can define your field initialization in multiple ways. Here is one typical way to do that.

A JavaScript interview question which can be fixed by 'let'

A very popular JavaScript interview question on Lexical scope and closure is like the follow.

Minimize the price (not the benefit) of type in Typescript

I watched Anders Hejlsberg introducing typescript in 2012. Then I thought I don't have the problem it tries to solve. Type in Javascript has not yet caused any problem for me, as I have unit test, renaming and intellisense is also not a problem for me, because I have webstorm. Then, I found that Douglas Crockford said something in google plus

TypeScript is duck typing.

When I see a bird that walks like a duck and swims like a duck and quacks like a duck, I call that bird a duck.

Leave $rootScope alone, use AngularJs Dependency Injection.

AngularJs brings dependency injection into UI development. It works very well until it is misused. Recently, I was working on an AngularJs project. One interesting thing is that some application settings is attached to $rootScope for convenient consumption. When I saw it, I felt this was so Déjà vu. The $rootScope has essentially become the new "window" object in the browser, where all global variables can be attached to. So I Googled about this and wanted to know whether other people have similar problem, and I found this question in StackOverflow, Global variables in AngularJS. It seems that this is a quite a common problem out there. So I wanted dig into it more.