Object Oriented JavaScript

// Object literals
const obj = {
  radius: 1,
  location: {
    x : 1,
    y : 2
  },
  draw:function () {
    console.log('draw');
  }
}


// we can also define an object using factories and constructurs

  //1) draw back of object literal syntax is that the object gets duplicate if it has a behaviour

  // Factory Function
  function createCircle(radius) {
    return {
      radius,
      draw: function () {
        console.log('Draw the circle');
      }
    }
  }

  const circle = createCircle(3);

  // Constrctor Function
  function Circle(radius) {
    this.radius = radius;
    this.draw = function() {
      console.log('draw');
    }
  }

  const another = new Circle(1);


  // Constructor Property
  // -> Every Object has a constrctor property and that reference the function that was used to create an object

  // Functions are Objects
  // -> check using Circle.__ we can access the members and methods

  // Primitives are copied by value
  // Reference types are copied by reference
  console.log(another);
  // Adding and removing properties
  another.location = {x : 1};
  another['now'] = 10;

  // iterate over object or propetry
  for(let key in another) {
    console.log(key , another[key]);
  }

  // iterate over only members and not methods
  for(let key in another) {
    if(typeof circle[key] !== 'function') {
      console.log(key , another[key]);
    }
  }

  // keys as an array
  const key = Object.keys(another);
  console.log(key);


  /// Abstraction

  // lets say if we have one object

  function Ractangle(radius) {
    this.height = 10;
    this.width = 20;
    this.radius = radius;
    let defaultLocation = {x: 10, y:20};
    this.computeOptimumLocation = function() {
      // here we are implementing a closure
      console.log("The computed location is", defaultLocation.x + 10);
      console.log("The computed location is", defaultLocation.y + 40);
    }
    this.draw = function() {
      console.log("Draw the function with height::" +this.height+ "width::" + this.width);
    }
  }

  const ract = new Ractangle(10);
  ract.computeOptimumLocation();


  // Getter and Setters

  function Triangle(radius) {
    this.height = 10;
    this.width = 20;
    this.radius = radius;
    let defaultLocation = {x: 10, y:20};
    this.computeOptimumLocation = function() {
      // here we are implementing a closure
      console.log("The computed location is", defaultLocation.x + 10);
      console.log("The computed location is", defaultLocation.y + 40);
    }
    this.draw = function() {
      console.log("Draw the function with height::" +this.height+ "width::" + this.width);
    }
    Object.defineProperty(this, 'defaultLocation', {
      get: function() {
        return defaultLocation;
      },
      set: function (value) {
        if(!value.x || !value.y) throw new Error("Invalid Location!");
        defaultLocation = value;
      }
    })
  }

  const tri = new Triangle(10);
   console.log("This is a default location::" ,tri.defaultLocation);
   tri.defaultLocation = {x : null , y: null};