TypeScript

name.js

function hello(name) {
    console.log("Hello " + name);
}
var firstName = "bob";
hello(firstName);
hello(firstName + " marley");
function concat(a, b) {
    return a + b;
}
var wcs = concat("Wild", concat(" Code", " School"));
console.log(wcs);

name.ts

function hello(name :string){
    console.log("Hello "+ name);
}

var firstName = "bob";

hello(firstName);
hello(firstName + " marley");

function concat(a : string, b: string){
    return a +b;
}

var wcs = concat("Wild", concat(" Code", " School"));
console.log(wcs);