Arrays in type script

This is a very c# type of code:

var bks: Book[] = new Book[2];

In Javascript / Typescript you don't allocate memory up front like that, and that means something completely different. This is how you would do what you want to do:

var bks: Book[] = [];bks.push(new Book());bks[0].Author = "vamsee";bks[0].BookId = 1;return bks.length;

Now to explain what new Book[2]; would mean. This would actually mean that call the new operator on the value of Book[2]. e.g.:

Book[2] = function (){alert("hey");}var foo = new Book[2]

and you should see hey. Try it

You can also do this as well (shorter cut) instead of having to do instance declaration. You do this in JSON instead.

class Book {    public BookId: number;    public Title: string;    public Author: string;    public Price: number;    public Description: string;}var bks: Book[] = []; bks.push({BookId: 1, Title:"foo", Author:"foo", Price: 5, Description: "foo"});   //This is all done in JSON.

A cleaner way to do this:

class Book {    public Title: string;    public Price: number;    public Description: string;    constructor(public BookId: number, public Author: string){}}

Then

var bks: Book[] = [    new Book(1, "vamsee")];