What is prototype and prototypal inheritance in JavaScript?

Every object has a hidden link to another object called its prototype. When you read a property that the object does not have, JavaScript looks for it in the prototype, then in the prototype of the prototype, and so on. This chain is prototypal inheritance.

function Person(name) {
  this.name = name;
}
Person.prototype.greet = function () {
  return "Hi, " + this.name;
};

const p = new Person("Robin");
console.log(p.greet());
console.log(Object.getPrototypeOf(p) === Person.prototype);

Output:

class and extends are a nicer syntax over the same prototype system. See Constructor Functions and Classes.

• Previous Interview Question
• Next Interview Question

---

Tutorials
No Content Found.

Exercises & Assignments
No Content Found.

Interview Questions & Answers
No Content Found.