let ballB;

let ballC;

​

function setup() {

  createCanvas(400, 400);

​

  ballA = new Ball(width/2, height/2);

  ballB = new Ball(width/2, height/2);

  ballC = new Ball(width/2, height/2);

}

​

function draw() {

  background(50);

​

  ballA.move();

  ballA.display();

  ballB.move();

  ballB.display();

  ballC.move();

  ballC.display();

}

​

class Ball {

  constructor(x, y) {

    this.x = x;

    this.y = y;

    this.dia = random(10, 30);

    this.xSpd = random(-2, 2);

    this.ySpd = random(-2, 2);

  }

  move() {

    this.x += this.xSpd;

    this.y += this.ySpd;

  }

  display() {

    ellipse(this.x, this.y, this.dia, this.dia);    

  }

}