/index.js
https://gitlab.com/zuitt-projects-pableo/s18 · JavaScript · 183 lines · 88 code · 38 blank · 57 comment · 0 complexity · 9b889631b254ffafb47ba7ef14aed7ad MD5 · raw file
- // A variable with multiple values
- // a: array
- let cartoons = ["Elmo", "Mickey", "Daisy", "Barbie"]
- // Javascript Objects
- // similar to an array, it also contains multiple values
- // unlike an array that uses index, objects use properties
- // with objects, we can easily give labels to each value
- // Structure or Syntax
- /*
- let objectName = {
- key : value,
- key : (function),
- key : object{
- key : value
- },
- key : [array]
- }
- */
- let cellphone = {
- name: "Nokia 3210",
- manufactureDate: 1999
- };
- console.log(cellphone);
- console.log(typeof cellphone);
- // Creating objects using a constructor function
- /*
- Syntax:
- function objectName(keyA, keyB){
- this.keyA = keyA;
- this.keyB = keyB;
- }
- */
- function Laptop(name, manufactureDate) {
- this.name = name;
- this.releaseDate = manufactureDate;
- };
- let laptop = new Laptop("Lenovo", 2008);
- console.log(laptop);
- // will create new object
- // new operator creates an instance of an object
- let laptop1 = Laptop("Asus", 2010);
- console.log(laptop1);
- // result: undefined
- // Creating empty objects
- let computer = {};
- let myComputer = new Object();
- console.log(computer);
- console.log(myComputer);
- // Accessing Array Objects
- let machines = [laptop, laptop1];
- // access the property of an object inside an array
- console.log(machines[0].name);
- // result: Lenovo
- // another way of accessing properties in an array
- console.log(machines[0]["releaseDate"]);
- // result: 2008
- // Initializing/ Adding/ Deleting/ Reassigning Object Properties
- let car = {};
- // Initializing/ Adding object properties
- // using dot notation
- car.name = "Honda Civic";
- console.log(car);
- // using square brackets
- car["manufactureDate"] = 2019;
- console.log(car);
- // Deleting object properties
- delete car["name"];
- console.log(car);
- // Mini-Activity
- car.brand = "Toyota";
- car.model = "Innova";
- car.color = "red";
- car.location = "Makati";
- console.log(car);
- // Reassigning object properties
- car.manufactureDate = 2005;
- console.log(car);
- // Object Methods
- // a method is a function which is a property of an object
- // they are also functions and one of the key differences they have is that methods are functions related to a specific object
- // methods are defined based on what an object is capable of doing and how it should work
- let person = {
- name: "Jin",
- talk: function(){
- console.log(`Hello my name is ${this.name}`)
- }
- };
- person.talk();
- let friend = {
- firstName: "Bam",
- lastName: "Jeon",
- address: {
- city: "Caloocan",
- country: "Philippines"
- },
- emails: ["bam@mail.com","jeonbam@gmail.com"],
- introduce: function(){
- console.log(`Hello my name is ${this.firstName} ${this.lastName}, I live in ${this.address.city}. My personal email is ${this.emails[0]}`)
- }
- };
- friend.introduce();
- // Real World Application
- // Scenario:
- // 1. Create a game that would have several pokemons to interact with each other
- // 2. Every pokemon should have stats, properties, functions
- let myPokemon = {
- name: "Bulbasaur",
- level: 3,
- health: 100,
- attack: 50,
- tackle: function(){
- console.log(`${this.name} tackled another pokemon`)
- console.log(`targetPokemon's health is now reduced`)
- },
- faint: function() {
- console.log(`${this.name} fainted`)
- }
- }
- myPokemon.tackle();
- myPokemon.faint();
- // Creating object with an object constructor
- function Pokemon(name, lvl, hp) {
- // Properties
- this.name = name;
- this.lvl = lvl;
- this.health = hp * 2;
- this.attack = lvl;
- // Methods
- this.tackle = function(target) {
- console.log(`${this.name} tackled ${target.name}`);
- console.log(`targetPokemon's health is now reduced`)
- // console.log(target.name)
- // console.log(this.name)
- }
- this.faint = function() {
- console.log(`${this.name} fainted`)
- }
- };
- // create new instances of the Pokemon object each with their unique properties
- let pikachu = new Pokemon("Pikachu", 3, 50);
- console.log(pikachu);
- let ratata = new Pokemon("Ratata", 5, 25);
- console.log(ratata);
- // Providing the "ratata" object as an argument to "pikachu" tackle method will create interaction between the two objects