【javascriptを使う人に知って貰いたい（エンジニア、デザイナ問わず）】Typescriptを使ってjavascriptをコンパイルを作成する。 ref: http://qiita.com/shinofara@github/items/4396b713ead5a4ae53b4

file0.txt

$ npm install -g typescript

file1.txt

$ vim sample.ts

class shop {
  price: number;
  num: number;
  constructor() {
    this.num = 10;
  }
  setPrice(price: number) {
    this.price = price;
  }
  calculatePrice() {
    var total: number = this.num * this.price;
    return this.price + '円のりんごを' + this.num + '個購入した場合' + total + '円です。';
  }
}
var sp = new shop();
sp.setPrice(1000);
document.body.innerHTML = sp.calculatePrice();

file2.txt

$ tsc sample.ts

file3.txt

$ ls sample.*
sample.js    sample.ts

file4.txt

$ vim sample.js 

var shop = (function () {
    function shop() {
        this.num = 10;
    }
    shop.prototype.setPrice = function (price) {
        this.price = price;
    };
    shop.prototype.calculatePrice = function () {
        var total = this.num * this.price;
        return this.price + '円のりんごを' + this.num + '個購入した場合' + total + '円です。';
    };
    return shop;
})();
var sp = new shop();
sp.setPrice(1000);
document.body.innerHTML = sp.calculatePrice();

file5.txt

$ vim sample.ts

class shop {
  price: number;
  num: number;
  constructor() {
    this.num = 10;
  }
  setPrice(price: number) {
    this.price = price;
  }
  calculatePrice() {
    var total: number = this.num * this.price;
    return this.price + '円のりんごを' + this.num + '個購入した場合' + total + '円です。';
  }
}
var sp = new shop();
sp.setPrice('1000');
document.body.innerHTML = sp.calculatePrice();


$ tsc sample.ts 
sample.ts(20,4): error TS2081: Supplied parameters do not match any signature of call target.
sample.ts(20,4): error TS2087: Could not select overload for 'call' expression.