javascript 如何在 jQuery 中解析日期字符串并检查它是否在过去
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How to parse date string in jQuery and check if it is in the past
提问by AJFMEDIA
I need to check if the date is in the past. This is what I have so far. JSfiddle here.
我需要检查日期是否在过去。这就是我迄今为止所拥有的。JSfiddle 在这里。
var date = "09/12/2013";
var d = new Date();
var month = d.getMonth() + 1;
var day = d.getDate();
var todaysDate = +(('' + day).length < 2 ? '0' : '') + day + '/' + (('' + month).length < 2 ? '0' : '') + month + '/' + d.getFullYear();
if (date < todaysDate) {
alert("in the past");
} else {
alert("in the future");
}
Currently it is saying that the date was in the past, when it should be in the future. I know I need to parse the string as a date, but not sure how.
目前它说日期是过去的，什么时候应该是将来的。我知道我需要将字符串解析为日期，但不确定如何解析。
Help?
帮助？
回答by T.J. Crowder
With that input format, you can't use a string comparison, because the least significant values are on the left. Note: I'm assuing that date is December 9th, 2013. If you're doing the American thing where it's September 12th, 2013, you'll have to adjust the indexes into partsbelow.
使用该输入格式，您不能使用字符串比较，因为最不重要的值在左侧。注意：我假设该日期是 2013 年 12 月 9 日。如果您在 2013 年 9 月 12 日的美国做事，则必须将索引调整为parts以下。
You couldreverse the fields:
您可以反转字段：
var date = "09/12/2013";
var parts = date.split('/');
date = parts[2] + "/" + parts[1] + "/" + parts[0];
...and then do your string comparison (being sure to construct the string for "today" in the same order — year/month/day).
...然后进行字符串比较（确保以相同的顺序构造“今天”的字符串——年/月/日）。
If you're going to do that, you could go ahead and finish the job
如果你打算这样做，你可以继续完成这项工作
var date = "09/12/2013";
var parts = date.split('/');
var date = new Date(parseInt(parts[2], 10), // year
parseInt(parts[1], 10) - 1, // month, starts with 0
parseInt(parts[0], 10)); // day
if (date < new Date()) {
// It's in the past, including one millisecond ago
}
...but of course, if you don't want the expression to be true for one millisecond ago, your string approach is fine.
...但当然，如果您不希望表达式在一毫秒前为真，那么您的字符串方法就可以了。
回答by dda
var date = new Date("09/12/2013");
var d = new Date();
console.log(date>d); // true
var date = new Date("09/12/2011");
console.log(date>d); // false
回答by EMMERICH
JavaScript's native Date comparator only works on Date objects, whereas you are comparing Strings. You should parse dateinto a Dateobject, and then compare it with d.
JavaScript 的本机日期比较器仅适用于日期对象，而您正在比较字符串。您应该解析date为一个Date对象，然后将其与d.
//define parse(string) --> Date
if(parse(date) < new Date()) {
alert('past');
} else {
alert('future');
}
