Js prototype

<div id="output"></div>
<script>
  String.prototype.affiche = function () { // => function don't permit "this"
    document.getElementById('output').innerHTML = this;
  }
  let text1 = "Text to display one";
  let text2 = "Text to display two";
</script>
<button onclick="text1.affiche();">text1.affiche()</button>
<button onclick="text2.affiche();">text2.affiche()</button>