​

function setup() {

  createCanvas(400, 400);

  bubble = new Bubble();

​

}

​

function draw() {

  background(220);

  bubble.show();

  bubble.bounce();

  bubble.speed();

}

​

class Bubble {

  constructor(){ //all variable go here

    this.xPos = 200;

    this.yPos = 200;

    this.rAdius = 50;

    this.xSpeed = 1;

    this.ySpeed = 2;

  }

  show(){

    ellipse(this.xPos,this.yPos,this.rAdius)

  }

  speed(){

    this.xPos += this.xSpeed

    this.yPos += this.ySpeed

  }

  bounce(){

    if(this.xPos<0 || this.xPos> width){

      this.xSpeed*=-1

    }

     if(this.yPos<0 || this.yPos> width){

      this.ySpeed*=-1

    }

  }

}