createCanvas(400, 400);

  frameRate(2);

}

​

let letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g']

let unitWidth = 10

let unitHeight = 10

​

function draw() {

  background(220);

  for (i=0; i<width; i+=15) {

    for (k=0; k<height; k+=15) {

      let x = round(random(letters.length-1))

      text(letters[x], i, k);

    }

  }

}