#Day68 of 100daysofcode
Today was Good Friday, and as per the name, it did turn out good as well… It was a sunny day, we went for long walks, and dined out 
It was a productive day as well… I was stressed out in the past 2-3 days, but today felt better. I continued with the Classes concept in Javascript and learned about inheritance and static methods. I also created a sample Library Catalog project which now I am thinking to add realm database in that as well
Review Notes on Classes
-
Classes are templates for objects.
-
Javascript calls a constructor method when we create a new instance of a class.
-
Inheritance is when we create a parent class with properties and methods that we can extend to child classes.
-
We use the
extendskeyword to create a subclass. -
The
superkeyword calls theconstructor()of a parent class. -
Static methods are called on the class, but not on instances of the class.
Library Project
Description:
Books-‘N-Stuff carries three different types of media: books, CDs, and movies. In this project, create a parent class named Media with three subclasses: Book , Movie , and CD . These three subclasses have the following properties and methods:
Book
- Properties :
author(string),title(string),pages(number),isCheckedOut(boolean, initiallyfalse), andratings(array, initially empty). - Getters : all properties have a getter
- Methods :
.getAverageRating(),.toggleCheckOutStatus(), and.addRating()
Movie
- Properties :
director(string),title(string),runTime(number),isCheckedOut(boolean, initiallyfalse), andratings(array, initially empty) - Getters : all properties have a getter
- Methods :
.getAverageRating(),.toggleCheckOutStatus(), and.addRating()
CD
- Properties :
artist(string),title(string),isCheckedOut(boolean, initiallyfalse), andratings(array, initially empty),songs(array of strings) - Getters : all properties have a getter
- Methods :
.getAverageRating(),.toggleCheckOutStatus(), and.addRating()
Code
class Media {
constructor(title){
this._title = title
this._isCheckedOut = false
this._ratings = []
}
get title() {
return this._title;
}
get isCheckedOut() {
return this._isCheckedOut;
}
get ratings(){
return this._ratings;
}
set isCheckedOut(value){
this._isCheckedOut = value
}
toggleCheckOutStatus() {
this._isCheckedOut = !this._isCheckedOut;
}
getAverageRating() {
let ratingsSum = this.ratings.reduce((currentSum, rating) => currentSum + rating, 0);
const ratingLength = this.ratings.length;
return ratingsSum/ratingLength;
}
addRating(rating){
this._ratings.push(rating);
}
}
class Book extends Media{
constructor(title, author, pages){
super(title)
this._author = author
this._pages = pages
}
get author() {
return this._author
}
get pages() {
return this._pages;
}
}
class Movie extends Media{
constructor(title, director, runtime){
super(title)
this._director = director
this._runtime = runtime
}
get director(){
return this._director;
}
get runtime(){
return this._runtime;
}
}
const historyOfEverything = new Book('A Short History of Nearly Everything', 'Bill Bryson', 544)
historyOfEverything.toggleCheckOutStatus()
console.log(historyOfEverything.isCheckedOut)
historyOfEverything.addRating(4)
historyOfEverything.addRating(5)
historyOfEverything.addRating(5)
console.log(historyOfEverything.getAverageRating())
const speed = new Movie('Speed', 'Jan de Bont', 116)
speed.toggleCheckOutStatus()
console.log(speed.isCheckedOut)
speed.addRating(1);
speed.addRating(1);
speed.addRating(5)
console.log(speed.getAverageRating())
I also finished Book Keeper App showing how embedded objects are created in Realm Schema and how they get synced to Atlas
Until tomorrow, 
which is pretty unusual of Ireland, where you get to experience 4 seasons in a day 
Today was fun time with legos… I absolutely enjoyed creating an amazing wall frame… I only regret buying an expensive one from Copenhagen Airport rather than from Amazon where it was cheaper 
so it was a little stressful day, thinking of all the work I have ahead of me 
to help me with the concepts I was stuck at, 
and another one is my friend 
Sometimes Life feels like a Detroit game, where one makes a decision and it changes the path forward… 
My tarot card prediction also highlighted the same