Getting to know p5.js editor

Code block:

function setup() {
  createCanvas(600, 400);
}

function draw() {
  background(220);
  strokeWeight(10);
  fill(255, 255, 0);
  rect(0,0,600,400);
}

Hidden code block:

function setup() {
  createCanvas(600, 300);
  noStroke();
}

function draw() {
  background(255);                                
  fill(255, 0, 0);                                
  circle(width/2, height/2, 0.6*height);          
}