ios - 如何在 Objective C 中比较日期格式的字符串

Question

我有两个字符串，格式为 Fri, 22 Jan 2016 10:46:50 +0530。我需要比较这两个字符串。如果可以通过将它们转换为日期来完成，我该如何编写 NSDateFormatter 样式。尝试了下面的代码。但没有工作。我将 newDate 和 currentDate 设为 nil。任何帮助将不胜感激。

NSString *dateString1 = @"Fri, 22 Jan 2016 10:46:50 +0530";
NSString *dateString2 = @"Fri, 21 Jan 2016 10:46:50 +0530";
NSDateFormatter *inputFormatter = [[NSDateFormatter alloc] init];
[inputFormatter setDateStyle:NSDateFormatterFullStyle];

NSDate *newDate = [inputFormatter dateFromString:dateString1];
NSDate *currentDate = [inputFormatter dateFromString:dateString2];

[inputFormatter release];

NSComparisonResult result = [newDate compare:currentDate]; // comparing two dates

if(result == NSOrderedAscending || result == NSOrderedSame) {
    NSLog(@"newDate is less or same");
}

Answer 1

使用 [inputFormatter setDateFormat:@"EEE, DD MMM yyyy HH:mm:ss z"];

    NSString *dateString1 = @"Fri, 22 Jan 2016 10:46:50 +0530";
    NSString *dateString2 = @"Fri, 22 Jan 2016 10:46:50 +0530";

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

    [inputFormatter setDateFormat:@"EEE, dd MMM yyyy HH:mm:ss Z"];

    NSDate *newDate = [inputFormatter dateFromString:dateString1];
    NSDate *currentDate = [inputFormatter dateFromString:dateString2];

    NSComparisonResult result = [newDate compare:currentDate]; // comparing two dates

    if(result == NSOrderedAscending || result == NSOrderedSame) {
        NSLog(@"newDate is less or same");
    }