Erasing text or lines?

p5.js Coding Questions
5

possibly
Unwanted beeping sounds with Vertex functions - #2 by kll can help.

now for the use of the 2 modes:

function draw() {
  background(); 
  // redraw all again 60 times per sec
}

or disabled

// background();

one tip, for showing changing text need to clean up background behind first
like p5.js Web Editor here.