限制下拉列表中每个选项的可选次数

<select id="mySelect">
  <option value="option1">Option 1</option>
  <option value="option2">Option 2</option>
  <option value="option3">Option 3</option>
</select>

<script>
  var select = document.getElementById("mySelect");
  var optionCounts = {
    option1: 2, // Option 1可选2次
    option2: 3, // Option 2可选3次
    option3: 1  // Option 3可选1次
  };
  var selectedCounts = {};

  select.addEventListener("change", function() {
    var selectedOption = select.value;
    if (selectedOption in selectedCounts) {
      if (selectedCounts[selectedOption] >= optionCounts[selectedOption]) {
        // 已达到选项可选次数上限，禁止选择该选项
        select.value = "";
        alert("该选项已达到可选次数上限！");
      } else {
        selectedCounts[selectedOption]++;
      }
    } else {
      selectedCounts[selectedOption] = 1;
    }
  });
</script>