我有幾個月的時間（一月到十二月）。選擇月份時，它將顯示該月份的 DIV。默認情況下，將顯示當前月份和相應的 DIV。到目前為止，我可以默認在下拉菜單中顯示當前月份，但我不知道為什么沒有顯示相應的DIV。Furthermore, when January is selected, the DIV displays, but then does not go away when another month is selected. 這只適用于 1 月份。HTML<select name="month" id="month">  <option value="0">January</option>  <option value="1">February</option>  <option value="2">March</option>  <option value="3">April</option>  <option value="4">May</option>  <option value="5">June</option>  <option value="6">July</option>  <option value="7">August</option>  <option value="8">September</option>  <option value="9">October</option>  <option value="10">November</option>  <option value="11">December</option></select><div class="hide" id="0">Jan content</div><div class="hide" id="1">Feb content</div><div class="hide" id="2">Mar content</div><div class="hide" id="3">Apr content</div><div class="hide" id="4">May content</div><div class="hide" id="5">Jun content</div><div class="hide" id="6">Jul content</div><div class="hide" id="7">Aug content</div><div class="hide" id="8">Sept content</div><div class="hide" id="9">Oct content</div><div class="hide" id="10">Nov content</div><div class="hide" id="11">Dec content</div>CSS.hide {    display: none;   }  JavaScript + jQueryvar CurrentDate=new Date();$("#month").val(CurrentDate.getMonth());document.getElementById('month').onchange = function() {    var i = 1;    var myDiv = document.getElementById(i);    while(myDiv) {        myDiv.style.display = 'none';        myDiv = document.getElementById(++i);    }    document.getElementById(this.value).style.display = 'block';};演示：https ://jsfiddle.net/mp61hbno/謝謝！