问单击此按钮将特定类的所有元素复制到剪贴板中？

EN

<div class="wrapper">
   <div class="copytext">I want to copy this text</div>
   <div class="nocopytext">I don't want to copy this text</div>
   <div class="copytext">I also want to copy this text<div>
</div>

<button onclick="copyText()">Copy only classes with copytext</button>
<div id="output"></div>

<script>

function copyText() {

  var outputText = "";
  var targets = document.getElementsByClassName('copytext');

  for( var i = 0; i < targets.length; i++ ) {
    outputText += targets[i].innerText;
  }

  var output = document.getElementById('output');
  output.innerText = outputText;
  var range = document.createRange();
  range.selectNodeContents(output);
  var selection = window.getSelection();
  selection.removeAllRanges();
  selection.addRange(range);
  document.execCommand('copy');
  output.style.display = 'none';

}

</script>