how to copy button onclick in javascript code example

Example 1: javascript text to clipboard

function copyToClipboard(text) {
   const elem = document.createElement('textarea');
   elem.value = text;
   document.body.appendChild(elem);
   elem.select();
   document.execCommand('copy');
   document.body.removeChild(elem);
}

Example 2: javascript copy to clipboard

function copyToClipboard(text) {
  var input = document.body.appendChild(document.createElement("input"));
  input.value = text;
  input.focus();
  input.select();
  document.execCommand('copy');
  input.parentNode.removeChild(input);
}

Example 3: js copy text to clipboard

function copy() {
  var copyText = document.querySelector("#input");
  copyText.select();
  document.execCommand("copy");
}

document.querySelector("#copy").addEventListener("click", copy);