this sketch draws a group of horizontal lines to the canvas.

add a conditional that makes every other line red.

*/

​

function setup() {

  createCanvas(600, 600);

  strokeWeight(10);

  background(255);

}

​

function draw() {

  for (let i = 0; i <= 10; i++) {

    stroke(0);

    line(0, 59 * i + 5, width, 59 * i + 5);

    if (i % 2 == 0) {

      stroke(255, 0, 0);

    }

    line(0, 59 * i + 5, width, 59 * i + 5);

  }

}