int main(int argc, const char * argv[]) {

@autoreleasepool {

NSDate *date=[NSDate date];

NSLog(@"%@",date);

//借助辅助类简单的格式化

NSCalendar *cal=[NSCalendar currentCalendar];

NSDateComponents *coms= [cal components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay fromDate:date];

NSLog(@"year:%ld,month:%ld,day:%ld",coms.year,coms.month,coms.day);

//不借助辅助类 格式化

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

formatter.dateFormat=@"yyyy年MM月dd日 HH:mm:ss";

//formatter.dateFormat=@"yyyy年MM月dd日 hh:mm:ss";

NSString *datestring=[formatter stringFromDate:date];

NSLog(@"%@",datestring);

//演示日期的加减法

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

dForma.dateFormat=@"yyyy年MM月dd日 hh:mm:ss";

//设置时间间隔

NSTimeInterval t=24*60*60;

//t:时间间隔可以设置为正负,正表示今天之后,负表示,今天之前

NSDate *tomorrow=[NSDate dateWithTimeIntervalSinceNow:t];

NSString *tomStr=[dForma stringFromDate:tomorrow];

NSLog(@"%@",tomStr);

}

return 0;

}