Add methods Array and Object Prototype

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript Objects</h2>

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

<script>

function Person(first, last, age, eye) {
    this.firstName = first;
    this.lastName = last;
    this.age = age;
    this.eyeColor = eye;
}
Person.prototype.name = function() {
    return this.firstName + " " + this.lastName
};

Array.prototype.getsize = function() {return this.length};

var myFather = new Person("John", "Doe", 50, "blue");
document.getElementById("demo").innerHTML = [1,33,2,23].getsize();
</script>

</body>
</html>