Prototypes and Prototype Chain — JS Technical Interview Questions & Answers

How JS objects inherit before/under classes.

Prototypes and Prototype Chain

  • Prototypes and Prototype Chain (js) is a JS topic. In plain words you use it for class Student in a tiny OOP file. Don’t start with a slogan — start with that picture.
  • Smallest example: class Student { constructor(name) {} }. Type it, run it, and say what you see. If you can do that from memory, you know Prototypes and Prototype Chain (js).
  • From the example next to this theory: How JS objects inherit before/under classes.
  • Trap: arrow function for a method that needs this. Fix that before you talk about advanced JS.
  • Viva: what is Prototypes and Prototype Chain (js)? Then show class Student { constructor(name) {} }. Then name the trap.

Technical Interview Tip: What is Prototypes and Prototype Chain (js)? Show this: class Student { constructor(name) {} }. Trap: arrow function for a method that needs this.

Code Examples for Prototypes and Prototype Chain

Prototypes and Prototype Chain — working example

class Animal {
  static kingdom = "Animalia";
  #secret = "private";
  constructor(name) { this.name = name; }
  speak() { return this.name + " speaks"; }
  reveal() { return this.#secret; }
}
class Dog extends Animal {
  speak() { return super.speak() + " (bark)"; }
}
const d = new Dog("Rex");
console.log(d.speak(), Animal.kingdom, d.reveal());
console.log(Object.getPrototypeOf(d) === Dog.prototype);

Prototypes and Prototype Chain — oOP in JS: constructors, prototypes, inheritance, statics, and private fields (#).

How to Explain Prototypes and Prototype Chain to an Interviewer

What is Prototypes and Prototype Chain (js)?

Used for class Student a tiny OOP file Not just the heading

Give one small example of Prototypes and Prototype Chain (js).

class Student { constructor(name) {} } How JS objects inherit before/under classes

What mistake do beginners make with Prototypes and Prototype Chain (js)?

arrow function for a method that needs this Show the fix

Where do you use Prototypes and Prototype Chain (js)?

a tiny OOP file class Student