如何从NSDate计算年龄

本文介绍了如何从NSDate计算年龄的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在制作一个应用程序，需要根据他们的生日找到某人的年龄。我有一个简单的 NSDate 但我如何用 NSDateFormatter 找到它？

I am working on an app that needs to find someones age depending on their birthday. I have a simple NSDate but how would I find this with NSDateFormatter?

推荐答案

- (NSInteger)ageFromBirthday:(NSDate *)birthdate { NSDate *today = [NSDate date]; NSDateComponents *ageComponents = [[NSCalendar currentCalendar] components:NSCalendarUnitYear fromDate:birthdate toDate:today options:0]; return ageComponents.year; }

NSDateFormatter 适用于格式化日期（呃！）。根据经验，只要您需要在 NSDate 上执行某些计算，就可以使用 NSCalendar 和相关联的类，例如 NSDateComponents 。

NSDateFormatter is for formatting dates (duh!). As a rule of thumb, whenever you need to perform some computation on an NSDate you use a NSCalendar and associated classes, such as NSDateComponents.