JSFiddle - React, Tailwind, and code Playground

JavaScript

function makeCheckbox(_, n){ 
  document.write('<p>'+n+'</p>'); 
}
document.write('sanity check');
[4,2].map(makeCheckbox);

document.write('why doesnt this work =(');
[undefined,undefined,undefined,undefined,undefined,undefined].map(makeCheckbox);