javascript - 如何格式化下拉列表中的日期？

Question

我想问一下如何将selectmonth的月份格式改为“September”而不是09

function myFunction() {
var d = new Date();
var month = new Array();
month[0] = "January";
month[1] = "February";
month[2] = "March";
month[3] = "April";
month[4] = "May";
month[5] = "June";
month[6] = "July";
month[7] = "August";
month[8] = "September";
month[9] = "October";
month[10] = "November";
month[11] = "December";
var x = month[d.document.getElementById("selectmonth").value];
var y = document.getElementById("selectyear").value;
document.getElementById("demo").innerHTML = "Quick summary for " + x + y ;
}

Answer 1

您在评论中说您的选择选项显示月份名称，所以大概这意味着您的选项如下:

<option value="09">September</option>

如果是这样，那么您可以获取所选项目的值和显示名称，如下所示:

var monthDropdown = document.getElementById("selectmonth");
var x = monthDropdown.value
var monthName = monthDropdown.options[monthDropdown.selectedIndex].textContent;

在上下文中:

function myFunction() {
  var monthDropdown = document.getElementById("selectmonth");
  var x = monthDropdown.value
  var monthName = monthDropdown.options[monthDropdown.selectedIndex].textContent;
  var y = document.getElementById("selectyear").value;
  document.getElementById("demo").innerHTML = "Quick summary for " + monthName + " " + y + " (the month number was " + x + ")";
}
document.querySelector("button").addEventListener("click", myFunction);

<select id="selectmonth">
  <option value="01">January</option>
  <option value="02">February</option>
  <option value="03">March</option>
  <option value="04">April</option>
  <option value="05">May</option>
  <option value="06">June</option>
  <option value="07">July</option>
  <option value="08">August</option>
  <option value="09">September</option>
  <option value="10">October</option>
  <option value="11">November</option>
  <option value="12">December</option>
</select>
<input id="selectyear" value="2016">
<button>Test</button>
<div id="demo"></div>