Demonstrating Knowledge of OOP using Inheritance, Polymorphism, and Encapsulation

oop.js

/***** 

INHERITANCE 

******/
class AnimalKingdom {

  constructor(name){
    this.speed = 0;
    this.name = name;
  }

  run(distance,time){
    this.speed = distance/time;
    console.log(`I am a ${this.name}. I am currently running with a speed of ${this.speed}ms-1.`);
  }

  stop(){
    this.speed = 0;
    console.log(`${this.name} stopped.`);
  }

}

// Inherit from AnimalKingdom
class Cheetah extends AnimalKingdom {
  hide() {
    console.log(`${this.name} hides! because he saw a Lion Approaching`);
  }
}

let cheetah = new Cheetah("cheetah");

cheetah.run(10,2); // cheetah inherits run from the Animalkingdom
cheetah.hide(); // cheetah hides!






console.log('#############')
console.log('#############')







/***** 

POLYMORPHISM - Method Overidding 

******/
class President {

  constructor(name){
    this.name = name;
    this.presidentAdvice = 'ADVICE - I am Buhari,Vote and Get A million Naira'
  }
  
  right() {
    console.log(`RIGHT - I am ${this.name}. As a citizen i have the right to choose who i vote for `);
  }

  opinion(text){
    console.log(`OPINION - My name is ${this.name}. ${text}`);
  }

  advice(){
    console.log(this.presidentAdvice);
  }

}

// Inherit from AnimalKingdom
class VicePresident extends President {
  advice(){
    console.log(`ADVICE - Vote for me ${this.name}. I will give you 2 Million `)
  }
}

let vp = new VicePresident("Osinbajo");
let text = 'I am not voting for Buhari, this year period'
vp.right(); 
vp.opinion(text)
vp.advice(); // Osinbajo is overriding buhari's Advice




console.log('#############')
console.log('#############')






/***** 

ENCAPSULATION

******/
class Calculator {

  constructor(name,age){
    var minAge = 20
    this.name = name;
    this.age = age;
  }

  getAge(){
    return this.age;
  }

  getAgeSum(){
    return this.getAge() + this.minAge;
  }

}

// Calculator
class AgeCalculator extends Calculator {
  print() {
    console.log(`My name is ${this.name}. Cummulative age is ${this.getAgeSum()}`);
  }
}

let user  = new AgeCalculator('mikel',10);

user.print() 
console.log('User Age = '+user.getAge()); 
console.log(user.minAge) // Undefined - You should not be able to get min age