* @name Setup and Draw

 * @arialabel Animated horizontal white line on a black background that moves from the bottom to the top of the screen

 * @description The code inside the draw() function runs continuously from top

 * to bottom until the program is stopped. The

 * code in setup() is run once when the program starts.

 */

let y = 100;

​

// The statements in the setup() function

// execute once when the program begins

function setup() {

  // createCanvas must be the first statement

  createCanvas(720, 400);

  stroke(255); // Set line drawing color to white

  frameRate(30);

}

// The statements in draw() are executed until the

// program is stopped. Each statement is executed in

// sequence and after the last line is read, the first

// line is executed again.

function draw() {

  background(0); // Set the background to black

  y = y - 1;

  if (y < 0) {

    y = height;

  }

  line(0, y, width, y);

}

​