Javascript 指令详解

如何操作 select 和 option

JS 码如下：

var yesDateYear = "2023";var yesDateMonth = "12";var yesDateDay = "31";var iDateYear = window.document.getElementById("iDateYear");var iDateMonth = window.document.getElementById("iDateMonth");var iDateDay = window.document.getElementById("iDateDay");for (var i = 0; i < iDateYear.length; i++) {    if (iDateYear.options[i].value == yesDateYear) {        iDateYear.options[i].selected = true;    }}for (var j = 0; j < iDateMonth.length; j++) {    if (iDateMonth.options[j].value == yesDateMonth) {        iDateMonth.options[j].selected = true;    }}for (var k = 0; k < iDateDay.length; k++) {    if (iDateDay.options[k].value == yesDateDay) {        iDateDay.options[k].selected = true;    }}

HTML 码如下：

<select name="dateYear" id="iDateYear"></select><select name="dateMonth" id="iDateMonth"></select><select name="dateDate" id="iDateDay"></select>