Misunderstood class declaration?

Question

JavaScript

Good morning, habralyudi!
I came across this code:

var Greeter = (function () {
    function Greeter(message) {
        this.greeting = message;
    }
    Greeter.prototype.greet = function () {
        return "Hello, " + this.greeting;
    };
    return Greeter;
})();

This seems to be a class declaration, but why is it better / worse than the “traditional” implementation?

var Greeter =  function(message) {
   this.greeting = message;
 }
 Greeter.prototype.greet = function () {
     return "Hello, " + this.greeting;
 };

PS: This code generates TypeScript

Answer 1

It's just that the class declaration is framed by a closure so as not to "hook" anything from the outside.