function class js 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 new function as class

// Javascript Function that behaves as class, with private variables
function Person(name){
    const birth = new Date();
    this.greet = () => `Hello my name is ${name}. I was born at ${birth.toISOString()}`;
}

const joe = new Person("Joe");
joe.greet(); // Hello my name is Joe. I was born at 2021-04-09T21:12:33.098Z
// The birth variable is "inaccessible" from outside so "private"

Example 4: javascript class

//JavaScript class: Here a quick code example

// Basic class
class Rectangle {
  
  // Constructor
  constructor(height, width) {
    // Member variables
    this.height = height;
    this.width = width;

    // Access static member variable
    Rectangle.count++;
  }
  
  // Getter
  get area() {
    return this.calcArea();
  }
  
  // Method
  calcArea() {
    return this.height * this.width;
  }

  // Static method
  static calcArea(width, height) {
    return width * height;
  }
}

// Static member variable
Rectangle.count = 0;


// Class instantiation
const square = new Rectangle(10, 10);

// Access member variable
console.log(square.height, square.width); // 10 10

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

// Call method
console.log(square.calcArea()); // 100


// Access static member variable
console.log(Rectangle.count); // 1

// Call static method
console.log(Rectangle.calcArea(15, 15));  // 225

Example 5: 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);
    }
  }

Example 6: javascript classes

class SayHelloTo {
  name (to) {
    console.log(`Hello ${to}`);
  }
  constructor (to) {
    this.name(to);
  }
}
const helloWorld = new SayHelloTo(World);