Object Prototypes

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript Objects</h2>

<p>You cannot add a new property to a constructor function.</p>

<p id="demo"></p>

<script>
function Person(first, last, age, eye) {
  this.firstName = first;
  this.lastName = last;
  this.age = age;
  this.eyeColor = eye;
}

Person.nationality = "English";

const myFather = new Person("ahmed", "hatem", 50, "blue");
const myMother = new Person("salah", "saleh", 48, "green");


document.getElementById("demo").innerHTML =
"The nationality of my father is " + myFather.nationality; 
</script>

</body>
</html>