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!// Class Inheritance in JavaScript
class Mammal {
constructor(name) {
this.name = name;
}
eats() {
return `${this.name} eats Food`;
}
}
class Dog extends Mammal {
constructor(name, owner) {
super(name);
this.owner = owner;
}
eats() {
return `${this.name} eats Chicken`;
}
}
let myDog = new Dog("Spot", "John");
console.log(myDog.eats()); // Spot eats chickenfunction Animal (name) {
this.name = name;
}
Animal.prototype.speak = function () {
console.log(`${this.name} makes a noise.`);
}
class Dog extends Animal {
speak() {
console.log(`${this.name} barks.`);
}
}
let d = new Dog('Mitzie');
d.speak(); // Mitzie barks.
// For similar methods, the child's method takes precedence over parent's method
class MyArray extends Array {
// Overwrite species to the parent Array constructor
static get [Symbol.species]() { return Array; }
}
let a = new MyArray(1,2,3);
let mapped = a.map(x => x * x);
console.log(mapped instanceof MyArray); // false
console.log(mapped instanceof Array); // true
const Animal = {
speak() {
console.log(`${this.name} makes a noise.`);
}
};
class Dog {
constructor(name) {
this.name = name;
}
}
// If you do not do this you will get a TypeError when you invoke speak
Object.setPrototypeOf(Dog.prototype, Animal);
let d = new Dog('Mitzie');
d.speak(); // Mitzie makes a noise.
class MyClass {
// class methods
constructor() { ... }
method1() { ... }
method2() { ... }
method3() { ... }
...
}