Javascript 使用 jquery 获取当前月份和日期
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Get current month and date using jquery
提问by Suraj Shrestha
I have two dropdownlist that hold months and years...
我有两个包含数月和数年的下拉列表...
$(document).ready(function () {
$('#Months option:eq(' + (new Date).getMonth() + ')').prop('selected', true);
alert((new Date).getMonth());
$('#Years option:eq(' + (new Date).getFullYear() + ')').prop('selected', true);
alert((new Date).getFullYear());
});
I wrote the JQuery script as above so that when my program runs the dropdown selected value must be the current month and year..
我写了上面的 JQuery 脚本，这样当我的程序运行时，下拉选择的值必须是当前的月份和年份..
but when i execute the program.. the alert gives 7 and 2012.. but in my view the current month is selected but the current year is not why?? and how can I make my dropdown to select current year??
但是当我执行程序时.. 警报给出了 7 和 2012.. 但在我看来，当前月份被选中，但当前年份不是为什么？以及如何让我的下拉菜单选择当前年份？
回答by snuffn
jQuery
jQuery
var d = new Date(),
n = d.getMonth(),
y = d.getFullYear();
$('#months option:eq('+n+')').prop('selected', true);
$('#years option[value="'+y+'"]').prop('selected', true);
HTML
HTML
?<select id="months">
<option value="1">January</option>
<option value="2">February</option>
<option value="3">March</option>
<option value="4">April</option>
<option value="5">May</option>
<option value="6">June</option>
<option value="7">July</option>
<option value="8">August</option>
<option value="9">September</option>
<option value="10">October</option>
<option value="11">November</option>
<option value="12">December</option>
</select>
<select id="years">
<option value="2011">2011</option>
<option value="2012">2012</option>
<option value="2013">2013</option>
</select>
回答by jussinen
Months are returned as an integer from 0 (January) to 11 (December): see http://www.java2s.com/Tutorial/JavaScript/0240__Date/DategetMonth.htm
月份作为从 0（一月）到 11（十二月）的整数返回：请参阅http://www.java2s.com/Tutorial/JavaScript/0240__Date/DategetMonth.htm
So the current month (August) would return 7. To be able to match up with the usual month index (meaning 1 to 12), use ((new Date()).getMonth() + 1).
因此当前月份（八月）将返回 7。为了能够与通常的月份索引（即 1 到 12）匹配，请使用((new Date()).getMonth() + 1).
As pointed out in the comments, I misunderstood the problem. The month is correct because of the zero-based array for months and the jquery selector :eq()being also zero-based.
正如评论中指出的那样，我误解了这个问题。月份是正确的，因为月份的数组从零开始，而 jquery 选择器:eq()也是从零开始的。
However as pointed in other answers, the year returned would not match :eq()which matches the nth element in the jquery selector. Using as suggested option[value=' + (new Date).getFullYear() + ')'would be better.
但是，正如其他答案中所指出的，返回的年份:eq()与 jquery 选择器中的第 n 个元素不匹配。按照建议使用option[value=' + (new Date).getFullYear() + ')'会更好。
回答by lqc
The :eq(N)part of the selector in jQuery selects Nth element (including 0th) in the matched set (which at that point would be #Years option). So unless you have more then 2012 options in the Yearsdropdown, this won't work.
的:eq(N)jQuery中选择第N个元素（包括0）级的匹配组（其在该点处将是选择器的一部分#Years option）。因此，除非Years下拉列表中有超过 2012 年的选项，否则这是行不通的。
It's better to select the option based on it's value: option[value=2012]or
最好根据其值选择选项：option[value=2012]或
just use $("#Years").val(2012), it's more readable and less code.
只需使用$("#Years").val(2012)，它的可读性更高，代码更少。
