var y = 200;

​

​

function setup() { 

  createCanvas(400, 400);

} 

​

function draw() { 

  background(220);

  fill(0);

  ellipse(x,y,50,50);

  //x = x + 1;

  if (x >= 400){

   x = 0; 

  }

}

​

​

function keyPressed() {

  if (keyCode === UP_ARROW) {

    y = y - 10;

  } else if (keyCode === DOWN_ARROW) {

   y = y + 10;

  }

  if (keyCode === LEFT_ARROW) {

    x = x - 5;

  } else if (keyCode === RIGHT_ARROW) {

    x = x + 5;

  }

}