using let and const example

CSS

* {
  box-sizing: border-box;
  transition: all 0.2s;
  scroll-behavior: smooth;
}

JS

function let_const(str) {
  "use strict";

  const sentence = str + " is random!";
  for(let i = 0; i < str.length; i+=2) {
    console.log(sentence);
    write_result(sentence);
  }

}
let_const("code");

// this is a common function just to write the content into the result div
function write_result(result) {
  var result_html = document.getElementById("result");
  result_html.innerHTML = result;
}

HTML

<div id='result' class='mb-3 alert alert-primary'>..</div>
<button onclick="let_const('code');" class='btn btn-primary mb-1'>Run Function</button>

Working Result

Test Result Below, check the console for more...