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 是否晚于前一个日期且早于 nextDate。 我该怎么做？

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

我想您正在使用 NSDate 类。

您可以使用 isEqualToDate 比较两个 NSDate 对象。还有 earlierDate 和 laterDate 检查当前日期是否大于上一个日期且小于下一个日期。

Answer 3

我只是用它来检查一下：

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

对我来说效果很好！谢谢@Luca Matteis 的提示“稍后日期：”

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 对象还实现了有据可查的 -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)");
}