如何以编程方式在iphone中获取当前年份的第一个日期

Question

我在iphone应用程序中工作，现在我想从当前日期获取当前年度和当前月份的第一个日期。      For（e.x：年度第一次：2013/01/01）     并且（e.x月份的第一个日期是：2013/12/01）

请帮我解决这个问题。感谢。

Answer 1

// This is your currentDate
NSDate *today = [NSDate date];

// NSDateFormatter to separate the Year and Month from currentDate
NSDateFormatter *df = [[NSDateFormatter alloc] init]
[df setDateFormat:@"yyyy"];

NSInteger currentYear = [[df stringFromDate:today] integerValue];
NSString *currentYearFirstDate = [NSString stringWithFormat:@"%d/01/01", currentYear];

[df setDateFormat:@"MM"];
NSInteger currentMonth = [[df stringFromDate:today] integerValue];
NSString *currentMonthFirstDate = [NSString stringWithFormat:@"%d/%d/01", currentYear, currentMonth];

// You can get date object from above string via using below date format
[df setDateFormat:@"yyyy/MM/dd"];

Answer 2

NSDateComponents *components = [calendar components:units fromDate:[NSDate date]];
[components setDay:1];
self.currentDate = [calendar dateFromComponents:components];
int m = components.month;
int y = components.year;
int d = components.day;

NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:@"yyyy MM dd"];
NSDate *firstDateOfMonth = [df dateFromString:[NSString stringWithFormat:@"%d %d 01",y,m]];
NSDate *firstDateOfYear = [df dateFromString:[NSString stringWithFormat:@"%d 01 01",y]];