使用javascript从下拉列表中获取多个值

<select id="mySelect" multiple>
  <option value="value1">Option 1</option>
  <option value="value2">Option 2</option>
  <option value="value3">Option 3</option>
  <option value="value4">Option 4</option>
</select>

var selectElement = document.getElementById("mySelect");
var selectedValues = [];

for (var i = 0; i < selectElement.options.length; i++) {
  if (selectElement.options[i].selected) {
    selectedValues.push(selectElement.options[i].value);
  }
}

console.log(selectedValues); // 输出选中的值