var x = 0

var indice = 0

var letras = ['a','b','c','d']

function setup() {

  createCanvas(400, 400);

  x = random(0,400)

  indice = parseInt(random(0,4))

}

​

function draw() {

  background(220);

​

  fill(255)

  ellipse(x,y,40,40)

  fill(0)

  text(letras[indice],x,y)

  y = y + 3

  if ( y > 400 ) {

    x = random(0,400)

    y=0

    indice = parseInt(random(0,4))

    console.log(indice)

  }

}