JavaScript is one of the most popular languages used by programmers all around the world. In this course, you'll be introduced to the Object-Oriented Paradigm of JavaScript. The course will discuss OOP in both, ES5 and ES6 versions of JavaScript. It begins with a basic introduction to what Object-Oriented programming is, followed by its comparison to other languages. It then introduces the new  OOP features available in ES6 version and compares it to the ES5 version. The course then discusses objects in JavaScript followed by the use of function as objects in OOP. It goes over the interesting concepts of prototype objects, data encapsulation, and classes. It then delves into the more complex concepts of inheritance in both the versions, including prototypal inheritance, prototype chaining, method overriding and mixins. The course is filled with interesting illustrations to help in your understanding of the concepts as well as numerous quizzes and exercises to help you practice.

Learn Object-Oriented Programming in JavaScript

# Problem Statement

A *constructor* function called `Student` is given with the following parameters:

* `marks1` 
* `marks2` 

>**Important Note**: Both `marks1` and `marks2` should be assigned to **protected** variables, `_marks1` and `_marks2`, during initialization. The [lesson](https://www.educative.io/collection/page/5429798910296064/5907042445295616/6034811330232320) on data encapsulation explains how to do so.

Next, you have to define the following methods such that they can be shared by all object instances created:

* `getMarks(markNumber)`: a method which should return `_marks1` if `markNumber` equals **1** and `_marks2`  if `markNumber` equals **2**.

* `calcTotal()`: the method should *return* the **sum** of `_marks1` and `_marks2`.


In this exercise, you have to calculate a student's total marks using the concept of prototypes in constructor functions.

Exercise 3: Calculate the Student's Total Marks

Problem Statement