javascript 时刻 .isAfter 没有正确返回
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Moment .isAfter not returning correctly
提问by Mdd
I have a string that is stored in UTC time. I am trying to see if this time is after the current UTC time. I am using momentjs and the isAfter() method returns the incorrect value when there is only 1 hour difference.
我有一个以 UTC 时间存储的字符串。我想看看这个时间是否在当前 UTC 时间之后。我正在使用 momentjs 并且 isAfter() 方法在只有 1 小时的差异时返回不正确的值。
The active_time variable happens at 15:00 utc. The current_time is set to 16:00 utc. So I think active_time.isAfter(current_time)should return falsebut it is returning true. How can I make it return false?
active_time 变量发生在 15:00 UTC。current_time 设置为 16:00 UTC。所以我认为active_time.isAfter(current_time)应该返回false但它正在返回true。我怎样才能让它回来false？
jsFiddle link: http://jsfiddle.net/Ln1bz1nx/
jsFiddle 链接：http: //jsfiddle.net/Ln1bz1nx/
Code:
代码：
//String is already in utc time
var active_time = moment('2015-06-04T15:00Z', 'YYYY-MM-DD[T]HH:mm[Z]');
//Convert current time to moment object with utc time
var current_time = moment( moment('2015-06-04T16:00Z').utc().format('YYYY-MM-DD[T]HH:mm[Z]') );
console.log('active_time =',active_time);
console.log('current_time =',current_time);
console.log( active_time.isAfter(current_time) ); //Why does this return true?
回答by Alexander Lindsay
Even though the first date string is utc, you still need to put the moment into utc mode before you compare. Take a look at the docs here: http://momentjs.com/docs/#/parsing/utc/
即使第一个日期字符串是 utc，您仍然需要在比较之前将时刻置于 utc 模式。看看这里的文档：http: //momentjs.com/docs/#/parsing/utc/
//String is already in utc time, but still need to put it into utc mode
var active_time = moment.utc('2015-06-04T15:00Z', 'YYYY-MM-DD[T]HH:mm[Z]');
//Convert current time to moment object with utc time
var current_time = moment.utc('2015-06-04T16:00Z', 'YYYY-MM-DD[T]HH:mm[Z]');
console.log('active_time =',active_time.format());
console.log('current_time =',current_time.format());
console.log( active_time.isAfter(current_time) );<script src="https://rawgit.com/moment/moment/develop/moment.js"></script>回答by Pierre Inglebert
If your dates are ISO8601 formatted or timestamp, don't use moment.isAfter. It's 150 times slower than comparing 2 dates objects : http://jsperf.com/momentjs-isafter-performance
如果您的日期是 ISO8601 格式或时间戳，请不要使用 moment.isAfter。它比比较 2 个日期对象慢 150 倍：http: //jsperf.com/momentjs-isafter-performance
var active_time = new Date('2015-06-04T15:00Z');
var current_time = new Date('2015-06-04T16:00Z');
console.log('active_time =',active_time);
console.log('current_time =',current_time);
console.log( active_time > current_time );
回答by dave
Look at the toDatemethod to see what the internal js date is:
看toDate方法看看内部js日期是什么：
console.log('active_time =',active_time.toDate());
console.log('current_time =',current_time.toDate());
console.log( active_time.isAfter(current_time) ); //Why does this return true?
active_time = Thu Jun 04 2015 15:00:00 GMT-0700 (Pacific Daylight Time)
current_time = Thu Jun 04 2015 09:00:00 GMT-0700 (Pacific Daylight Time)
true
It's going to depend on what timezone you are in
这将取决于您所在的时区
