如何选择多选表单中的所有选项？

<form id="myForm">
  <input type="checkbox" name="option1" value="Option 1"> Option 1<br>
  <input type="checkbox" name="option2" value="Option 2"> Option 2<br>
  <input type="checkbox" name="option3" value="Option 3"> Option 3<br>
  <input type="button" value="Select All" onclick="selectAllOptions()">
</form>

<script>
function selectAllOptions() {
  var checkboxes = document.querySelectorAll('input[type="checkbox"]');
  checkboxes.forEach(function(checkbox) {
    checkbox.checked = true;
  });
}
</script>