ios - NSDateFormatter 的 NSDate 输出不同

Question

我在使用 NSDate 时遇到了一些问题，实际上我只需要它来验证它是一个有效日期，因为如果它是一个无效日期，date 实例会返回零。但是

NSString *textValue = @"13/12/2014";

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"MM/dd/yyyy"];

// this should cause the output to have no time
[formatter setTimeStyle:NSDateFormatterNoStyle]; 
formatter.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US"];
[formatter setCalendar:[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]];
[formatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];

NSDate *date = [formatter dateFromString:textValue];

date 的结果是 2015-01-12 00:00:00 +0000

我期望的结果应该是:nil

Answer 1

NSString *textValue = @"1/12/2014"; 
NSString *textValue1 = @"15/12/2014"; 
NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; 
[formatter setDateFormat:@"MM/dd/yyyy"]; 
NSDate *date = [formatter dateFromString:textValue]; 
NSLog(@" >> %@ ",date);
NSDate *date1 = [formatter dateFromString:textValue1]; 
NSLog(@" >> %@ ",date);