Why do I need prototype here?

Question

can someone explain what's the difference between this:

<script>
function Employee() {
  this.name = "serj";

}

function Manager() {
 Employee.call(this);
  this.dept = "general";
}

var jim = new Manager;
console.log(jim.name); //serj
</script>

And this:

<script>
function Employee() {
  this.name = "serj";
}

Manager.prototype = Object.create(Employee.prototype);

function Manager() {
  Employee.call(this);
  this.dept = "general";
}

var jim = new Manager;
console.log(jim.name); //serj
</script>

So the question is why should I create a prototype?If manager calls employee and all works fine?

Answer 1

Calling the constructor function for Employee will run all the code that is inside that function. It won't perform all the side effects (i.e. creating a new object, assigning it to this and making it an instance of Employee … and you wouldn't want it to because you want it to be an instance of Manager).