function setup() {

  createCanvas(600, 600);

  ball1 =new Ball();

}

​

function draw() {

  background(220);

  ball1.move();

  ball1.display()

}

​

class Ball{

  constructor(){

    this.x =100;

    this.y =100;

    this.Xspeed =2;

    this.Yspeed =2;

  }

  move(){ 

  this.x=this.x +this.Xspeed ;

  this.y =this.y+this.Yspeed ;

  if(this.x>=600){

      this.Xspeed =this.Xspeed *(-1)

}

    if(this.y>=600){

      this.Yspeed =this.Yspeed *(-1)

}

  }

  display() {

    fill('red');

    ellipse(this.x, this.y, 20, 20); 

  }

}