Quick JavaScript Crash Course - Modern and Advanced JavaScript - Prototypal-Chains

The video tutorial explains JavaScript's prototype-based inheritance, starting with an introduction to prototypes and their role in object creation. It provides examples of accessing prototype methods and discusses methods to access prototype objects. The tutorial demonstrates adding methods to prototypes and explains the prototype chain, highlighting how objects inherit properties from parent prototypes. The session concludes with a summary of prototypal inheritance concepts, emphasizing JavaScript's object-based nature.

What is a prototype in JavaScript?

• A function that creates objects

• A special object linked to other objects

• A method to access object properties

• A variable that stores data

How are methods like 'toString' accessed in JavaScript objects?

• Directly from the object

• Through the object's prototype

• By importing them from a library

• By defining them in the object

Which method was introduced in ES5 to access an object's prototype?

• Object.assign

• Object.getPrototypeOf

• Object.defineProperty

• Object.create

What happens when a new method is added to a prototype?

• It replaces existing methods in the prototype

• It is not accessible by any object

• It becomes available to all objects linked to that prototype

• It is only available to the object it was added to

How does JavaScript find a method that is not in the object itself?

• It searches in the global scope

• It throws an error

• It creates the method dynamically

• It looks in the object's prototype

What is the prototype of an array in JavaScript?

• Object.prototype

• Array.prototype

• String.prototype

• Function.prototype

What is the relationship between arrays and objects in JavaScript?

• Arrays are classes

• Arrays are functions

• Arrays are a type of object

• Arrays are not objects

What is the final link in a prototypal chain?

• Undefined

• Null

• Object

• Array

What type of inheritance does JavaScript use?

• Module-based inheritance

• Interface-based inheritance

• Prototype-based inheritance

• Class-based inheritance

What is the significance of the 'null' prototype?

• It is the starting point of all objects

• It is a default prototype for functions

• It indicates the end of a prototype chain

• It is used to create new objects