Class 31

Question 1

What is an object?

Answer 1

Collection of variables (properties) and functions (methods)

Question 2

How to create an object? (Use stopwatch as an example)

Answer 2

Using literal notation
let stopwatch = {}

Question 3

How to create property and method of an object? (Use stopwatch as an example)

Answer 3

Using a dot notation
stopwatch.currentTime = 12
stopwatch.tellTime = function(time) {
console.log(“The current time is …}

Question 4

How to make a lot of objects?

Answer 4

Use a constructor (or a class)

Question 5

What is encapsulation?

Answer 5

The process of storing functions (methods) with their associated data (properties) - in one thing (object)

Question 6

What is abstraction?

Answer 6

Hide details and show essentials

Question 7

What is the keyword super for?

Answer 7

Call the constructor of its parents to access parents’ properties and methods (enable us to not have to repeat a lot of codes)

Question 8

What is inheritance?

Answer 8

Make a class from another class for a hierarchy of classes that share a set of properties and methods