TypeScript: a language for application-scale JavaScript development(typescriptlang.org)

    function f() {
        return "Hello World!";
    }

    function f(s: string) {
        return s;
    }

    declare var document;

    interface BankAccount {
        balance: number;
        deposit(credit: number): number;
    }
    
    class CheckingAccount extends BankAccount {
        constructor(balance: number) {
            super(balance);
        }
        writeCheck(debit: number) {
            this.balance -= debit;
        }
    }

    module M {
        var s = "hello";
        export function f() {
            return s;
        }
    }

    (x) => { return Math.sin(x); }

    null * 7

    7[2]

    7["a"]

    (x) => { return Math.sin(x); }

    module M {
      var s = "hello";
      export function f() {
        return s;
      }
    }

  "Why is [Microsoft] putting time and effort into 
  changing JavaScript when the DOM is what needs fixing?"

    /*!
        © Microsoft. All rights reserved.

        This library is supported for use in Windows Store apps only.

        Build: 1.0.8514.0.win8_rtm.120711-1900
  
        Version: Microsoft.WinJS.1.0
    */

  interface person{
	firstname;
	lastname;
  }

  interface apple{
	colour;
  }

  function hello(p : person){
	alert("hello " + p.firstname);
  }

  var aPerson = {firstname: "joe", lastname : "blogs"};
  var anApple = {color: "red"};

  var foo;
  if(true){
	foo = anApple;
  }

  hello(foo);

   new Greeter("World");

   new Greeter(5);

    $ t
    command not found