iOS时间以yyyy-MM-dd格式输出的两种方法代码

//方法一

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

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

        //    [formatter setDateFormat:@"yyyy-MM-dd hh:mm:ss"];

        NSString * locationString=[formatter stringFromDate:[NSDate date]];

        NSLog(@"今天日期是:%@",locationString);

        

        //方法二：

        NSCalendar *calendar = [[NSCalendaralloc] initWithCalendarIdentifier:NSGregorianCalendar];

        NSDate *now;

        NSDateComponents *comps = [[NSDateComponentsalloc] init];

        NSInteger unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekdayCalendarUnit |

        NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;

        now=[NSDate date];

        comps = [calendar components:unitFlags fromDate:now];

        NSLog(@"comps=%@",comps);

        int year=[comps year];

        int week = [comps weekday];

        int month = [comps month];

        int day = [comps day];

        int hour = [comps hour];

        int min = [comps minute];

        int sec = [comps second];

        NSLog(@"year=%d,week=%d,month=%d,day=%d,hour=%d,min=%d,sec=%d",year,week,month,day,hour,min,sec);

        NSLog(@"今天日期是:%d-%d-%d",year,month,day);