​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(0);

​

  // make a circle

  circle(xPosition, 200, 150);

​

  xPosition += 1;

​

  // if the xPosition is greater than 400

  // we will set it back to zero

  if (xPosition > 400) {

    xPosition = 0;

  }

}

​