Voice of a Developer: JavaScript Objects

Introduction

JavaScript is a language of the Web. This series of articles will talk about my observations learned during my decade of software development experience with JavaScript. What mistakes a developer generally makes and what differences they should be aware of. In part 1, we learned about Data Types and touched on Objects. But part 2 will focus in detail on Objects. You can go through Part 1 from here,

Voice of a Developer: JavaScript Data Types.

Q: Can you use save as a reference in Javascript like we have in other programming languages?

Ans Yes, let’s go back in C / C++ days where we have a concept of pointers, ex int x=49;

ptr = &x; This means that address of x is stored in ptr.

Therefore, ptr is pointing to an integer. The advantage of this is you could change the value in x via a pointer Ex *ptr=50;

printf(“%d”, x); // 50 Ex

> var person = {name: "Sumit"};

> console.log(person.name); // Ravi The variable is a reference, not a value

Object Own and Inherited Properties

The own properties are properties that were defined on the object, while the inherited properties were inherited from the object’s Prototype object. We learned about own properties in part 1, ex- person.name // own property Prototypal inheritance – Inherited property In most OOPS based languages, classes inherit from classes. In Javascript, it’s prototype-based. Objects inherit from Objects. And, we know an object is a prototype of classes. Therefore, it’s the prototypical based inheritance

Q: How do we implement prototypal inheritance?

Ans: Use the property called __proto__ Ex > var automobile = {engine: true};