从出生日期提取的年龄始终不一致 [英] Age extracted from birth date always off by inconsistent amount

问题描述

我正在使用以下代码将用户提供的生日转换为当前日期的等效年份。多年来，输出始终不一致，而在几天和几个月中，输出总是非常大。

I'm using the following code to convert a user-supplied birthdate to its equivalent years from the current date. The output is always off by an inconsistent amount in years and very large numbers in days and months.

NSDateFormatter *tempFormatter = [[NSDateFormatter alloc] init];
[tempFormatter setDateFormat:@"yyyy-mm-dd hh:mm:ss"];
NSDate *birthDate = [tempFormatter dateFromString:[NSString stringWithFormat:@"%@-%@-%@ 01:00:00",self.birthYear.text,self.birthMonth.text,self.birthDay.text]];

NSDate* now = [NSDate date];
NSDateComponents* ageComponents = [[NSCalendar currentCalendar]
                                   components:NSYearCalendarUnit
                                   fromDate:birthDate
                                   toDate:now
                                   options:0];
NSInteger years = [ageComponents year];
NSInteger days = [ageComponents day];
NSInteger months = [ageComponents month];
NSLog(@"Years: %ld, Days: %ld, Months: %ld",years,days, months);

输入 06-16-1986时输出的内容以下

年份：28，天数：9223372036854775807，月份：9223372036854775807

Years: 28, Days: 9223372036854775807, Months: 9223372036854775807

年份减少1，而月份和日期产生的数字非常大。我在不同的日期都遇到同样的问题。例如， 12-07-1989 产生

The year is off by 1 and the months and days are producing extremely large numbers. I get the same issue using various dates. For example, "12-07-1989" produces

年：25，天：9223372036854775807，月份：9223372036854775807

Years: 25, Days: 9223372036854775807, Months: 9223372036854775807

我在这里做什么错了？

推荐答案

问题出在这行上

NSDateComponents* ageComponents = [[NSCalendar currentCalendar]
                                   components:NSYearCalendarUnit
                                   fromDate:birthDate
                                   toDate:now
                                   options:0];

如果您想要月份&要计算的天数，您需要将其包括在这样的组件中

if you want month & days to be calculated you need to include that in the components like this

NSDateComponents* ageComponents = [[NSCalendar currentCalendar]
                                       components:( NSYearCalendarUnit | NSDayCalendarUnit | NSMonthCalendarUnit) 
                                       fromDate:birthDate
                                       toDate:now
                                       options:0];

您的格式对于月份字符串也是错误的

also your format is wrong for month string

[tempFormatter setDateFormat:@"yyyy-mm-dd hh:mm:ss"];

应更正为

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

现在您将获得正确的日期。

now you will get correct date.

说明。苹果文档中提到的
是基于1的。因此，如果您不提供值，则会将1设置为默认值。因此，您之前的月份格式为 mm，并且未正确设置生日月份，因此为1986-01-16，所以现在为2014-04-01（在新加坡）。所以你得到28年是正确的。

explanation. as mentioned on apple documentation these are 1-based. so incase you dont provide a value it will put 1 as default. so earlier your month format was "mm" and it was not correctly setting a month for the birthday hence it was 1986-01-16 so now its 2014-04-01 (in singapore). So you get 28 years which is correct.

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