比较两个日期

Question

如何比较两个不同的日期以找出较晚的日期？例如，在date1中，我将在下载一些数据后存储一个日期，在date2中，我将存储当前日期。然后我需要检查哪个更大/更晚：类似于 if(date1>date2)。

Answer 1

像这样的东西：

    NSDate* timeNow = [NSDate date];

    // If less than 30 seconds, do something
    if ([timeNow timeIntervalSinceDate:anEarlierTime] < 30.0f)
    {
        // Do something
    }

Answer 2

您可以使用 NSDate 的比较：方法：

NSComparisonResult result = [Date2 compare:Date1];

if(result==NSOrderedAscending)
    NSLog(@"Date1 is in the future");
else if(result==NSOrderedDescending)
    NSLog(@"Date1 is in the past");
else
    NSLog(@"Both dates are the same");

Answer 3

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 4

这是我用来比较日期和时区的方法，并使用 iOS 6 为我工作

        NSComparisonResult result = [timeStamp compare:serverDate];
        NSDateFormatter *df = [[NSDateFormatter alloc] init];
        [df setDateFormat:@"yyyy-MM-dd HH:mm:ss z"];
        switch (result)
        {
            case NSOrderedAscending:
                NSLog(@"%@ is greater than %@", [df stringFromDate:serverDate], [df stringFromDate:timeStamp]);
                break;
            case NSOrderedDescending:
                NSLog(@"%@ is less %@", [df stringFromDate:serverDate], [df stringFromDate:timeStamp]);
                break;
            case NSOrderedSame:
                NSLog(@"%@ is equal to %@", [df stringFromDate:serverDate], [df stringFromDate:timeStamp]);
                break;
            default:
                NSLog(@"erorr dates %@, %@", [df stringFromDate:serverDate], [df stringFromDate:timeStamp]);
                break;
        }