JSFiddle - React, Tailwind, and code Playground

HTML

<div id="results">

</div>

JavaScript

let inputs = {
  'notSanitized': "1 < 10",
  'sanitized': "1 &lt; 10",
  'injection': "<a href=\"evil.com\">Free iPhone click here<\/a>"
}

let placements = {
  'createTextNode': (elt, input) =>
    elt.appendChild(document.createTextNode(input)),
  'innerHTML': (elt, input) =>
    (elt.innerHTML = input),
}

let results = document.getElementById('results')
for(let inp in inputs) for(let plc in placements) {
  let h5 = document.createElement('h5')
  results.appendChild(h5)
  let desc = inp + ' placed via ' + plc + ':'
  h5.appendChild(document.createTextNode(desc))

  let p = document.createElement('p')
  results.appendChild(p)
  placements[plc](p, inputs[inp])
}