js class syntax code example

Example 1: javascript class

class ClassMates{
	constructor(name,age){
    	this.name=name;
      	this.age=age;
    }
  	displayInfo(){
    	return this.name + "is " + this.age + " years old!";
    }
}

let classmate = new ClassMates("Mike Will",15);
classmate.displayInfo();  // result: Mike Will is 15 years old!

Example 2: js class

class Car {
  constructor(brand, speed) {
    this.brand = brand
    this.speed = speed
  }
  speedUp() {
    this.speed += 5
    console.log(`The ${this.brand} is travelling at ${this.speed} mph`)
  }
  slowDown() {
    this.speed -= 5
    console.log(`The ${this.brand} is travelling at ${this.speed} mph`)

  }
}
const redCar = new Car('toyota', 0)
redCar.speedUp() // result: The toyota is travelling at 5 mph
redCar.slowDown() // result: The toyota is travelling at 0 mph

Example 3: javascript create class

class Person {
 constructor(name, age) {
   this.name = name;
   this.age = age;
 }
  present = () => { //or present(){
  	console.log(`Hi! i'm ${this.name} and i'm ${this.age} years old`) 
  }
}
let me = new Person("tsuy", 15);
me.present();
// -> Hi! i'm tsuy and i'm 15 years old.

Example 4: javascript class

class Rectangle {
  constructor(height, width) {
    this.height = height;
    this.width = width;
  }
  // Getter
  get area() {
    return this.calcArea();
  }
  // Method
  calcArea() {
    return this.height * this.width;
  }
}

const square = new Rectangle(10, 10);

console.log(square.area); // 100

Example 5: es6 class example

'use strict' 
class Polygon { 
   constructor(height, width) { 
      this.h = height; 
      this.w = width;
   } 
   test() { 
      console.log("The height of the polygon: ", this.h) 
      console.log("The width of the polygon: ",this. w) 
   } 
} 

//creating an instance  
var polyObj = new Polygon(10,20); 
polyObj.test();

Example 6: javascript classes

//private but is a good example
class includes {
    constructor(){}
  
    inculde_apps(file) { 
      var script  = document.createElement('script'); 
      script.src  = "ext/apps/"+file; 
      script.type = 'text/javascript'; 
      document.getElementsByTagName('body').item(0).appendChild(script);
    } 
    
    inculde_scripts(file) { 
      var script  = document.createElement('script'); 
      script.src  = "ext/scripts/"+file; 
      script.type = 'text/javascript'; 
      document.getElementsByTagName('body').item(0).appendChild(script);
    } 
    
    inculde_css(file) { 
        var script  = document.createElement('link'); 
        script.rel  = "stylesheet"; 
        script.type = 'text/css'; 
        script.href = "css/"+file;
        document.getElementsByTagName('head').item(0).appendChild(script);
    }
  }