'https://discourse.processing.org/t/create-input-accept-numbers-only/9624',

'https://p5js.org/reference/#/p5/input',

'https://p5js.org/reference/#/p5/int',

'https://www.w3schools.com/jsref/jsref_isnan.asp' ]

​

var aint = 0;

​

//                                   Open your console to see the output

function setup() {

  createCanvas(500, 150);

  for (var t=0; t< reflist.length;t++) print(reflist[t]);

  var inp = createInput('');

    inp.position(width/2, height-30);

  inp.input(myInputEvent);

}

​

function myInputEvent() {

  console.log('you are typing: ', this.value());

  var test = int(this.value());

  if (!isNaN(test)) {

    aint = test; // overwrite if ( begin with ) "Good Int Number" only

    fill(random(127, 200), random(127, 200), random(127, 200));

  } else {

    console.log('ERROR: not start with number');

  }

}

​

function draw() {

  background(0, 0, 80);

  textSize(80);

  stroke(200, 0, 0);

  strokeWeight(7);

  text(aint, 10, 80);

}