let x, y;

let xSpd, ySpd;

​

​

function setup() {

  createCanvas(400, 400);

  background(220);

  dia = 30;

  x = 250;

  y = 250;

  xSpd = random(-5, 5); 

  xSpd = random(-5, 5);

}

​

function draw() {

  background(220); // comment out to see how the circle moves

  x = x + xSpd;

  y = y + ySpd;

​

  // make it bounce

  if(x<0 || x > width){

    xSpd = xSpd * -1; // reverses movement direction when hitting edge of screen

  }

  if(y<0 || y > height){

    ySpd = ySpd * -1;

  }

  circle(x, y, dia);

}