如何在iOS中获取当年的开始日期

Question

我不知道如何使用NSDate或NSCalendar在这种情况下.
帮我解决这个问题.

Answer 1

这可以比其他答案更清晰:

NSDate *startOfYear;

[[NSCalendar currentCalendar] rangeOfUnit:NSCalendarUnitYear startDate:&startOfYear interval:0 forDate:[NSDate date]];

startOfYear 现在在今年的1月1日午夜举行.

Answer 2

-(NSDate *)getFirstDateOfCurrentYear
 {
  //Get current year
  NSDate *currentYear=[[NSDate alloc]init];
  currentYear=[NSDate date];
  NSDateFormatter *formatter1 = [[NSDateFormatter alloc] init];
  [formatter1 setDateFormat:@"yyyy"];
  NSString *currentYearString = [formatter1 stringFromDate:currentYear];

  //Get first date of current year
  NSString *firstDateString=[NSString stringWithFormat:@"10 01-01-%@",currentYearString];
  NSDateFormatter *formatter2 = [[NSDateFormatter alloc] init];
  [formatter2 setDateFormat:@"hh dd-MM-yyyy"];
  NSDate *firstDate = [[NSDate alloc]init];
  firstDate = [formatter2 dateFromString:firstDateString];

  return firstDate;
 }