如何比较两个日期？

Question

我有三个日期：（1）previousDate（2）currentDate（3）nextDate，我想检查currentDate是否晚于上一个日期，早于nextDate。 我怎么做？

Answer 1

 NSDateFormatter *df= [[NSDateFormatter alloc] init];

[df setDateFormat:@"yyyy-MM-dd"];

NSDate *dt1 = [[NSDate alloc] init];

NSDate *dt2 = [[NSDate alloc] init];

dt1=[df dateFromString:@"2011-02-25"];

dt2=[df dateFromString:@"2011-03-25"];

NSComparisonResult result = [dt1 compare:dt2];

switch (result)

{

     case NSOrderedAscending: NSLog(@"%@ is greater than %@", dt2, dt1); break;

     case NSOrderedDescending: NSLog(@"%@ is less %@", dt2, dt1); break;

     case NSOrderedSame: NSLog(@"%@ is equal to %@", dt2, dt1); break;

     default: NSLog(@"erorr dates %@, %@", dt2, dt1); break;
}

Answer 2

我想你正在使用NSDate类。

您可以使用isEqualToDate来比较两个NSDate对象。 而且，检查currentdate的earlyDate和laterDate比前一个日期更大，并且小于下一个日期。

Answer 3

我只是用它来检查它：

if ([[currentDate laterDate:nextDate] isEqualToDate:nextDate]) {
    NSLog(@"currentDate is earlier than nextDate");
}
if ([[currentDate laterDate:previousDate] isEqualToDate:currentDate]) {
    NSLog(@"currentDate is later then previousDate");
}

对我来说工作得很好！ 感谢@Luca Matteis暗示“LaterDate：”

Answer 4

我们可以在swift 5.0中轻松比较两个日期

    switch dateOld.compare(dateNew) {
    case .orderedAscending:
        // Put your code for greater
        break

    case .orderedDescending:
        // Put your code less
        break;

    case .orderedSame:
        // Put your code for equal
        break
}

Answer 5

NSDate对象还实现了记录良好的-compare：方法。

Answer 6

只需使用NSDate的compare消息执行两次比较：

if ([previousDate compare:currentDate] == NSOrderedAscending &&
    [nextDate compare:currentDate] == NSOrderedDescending) {
    NSLog(@"current date is in between previous and next date (non-inclusive)");
}