Class syntax in Javascript - Cheat Sheet & Quick Revision

Recall & Review

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What is a class in JavaScript?

A class is a blueprint for creating objects. It defines properties and methods that the created objects will have.

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How do you define a class in JavaScript?

Use the <code>class</code> keyword followed by the class name and curly braces. Inside, define a <code>constructor</code> method and other methods.

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What is the purpose of the constructor method in a class?

The constructor method runs automatically when you create a new object from the class. It sets up initial values for the object.

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How do you create an object from a class?

Use the <code>new</code> keyword followed by the class name and parentheses. For example: <code>const obj = new ClassName();</code>

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Can class methods access properties of the object? How?

Yes, class methods use <code>this</code> to access the object's properties and other methods.

Which keyword is used to define a class in JavaScript?

A define

B function

C object

D class

The class keyword is used to define a class.

What does the constructor method do?

A Initializes new objects

B Deletes objects

C Creates a new class

D Calls other methods

The constructor method initializes new objects when created.

How do you create an object from a class named Car?

A const car = new Car();

B const car = Car();

C const car = create Car();

D const car = class Car();

Use new Car(); to create an object from the class.

Inside a class method, how do you refer to the current object?

A self

B current

C this

D object

The keyword this refers to the current object inside class methods.

Which of these is NOT true about JavaScript classes?

A Classes can have methods

B Classes are functions

C Classes can have constructors

D Classes are blueprints for objects

Classes are special syntax, not regular functions, even though under the hood they use functions.

Explain how to create a class with a constructor and a method in JavaScript.

Think about the basic structure of a class and how you make objects from it.

Describe the role of the this keyword inside class methods.

Consider how methods know which object's data to use.