下午剛發(fā)生一個(gè)bug, 用戶生日日期是"1991-04-14", 在年齡顯示那里, 本該直接展示年齡, 結(jié)果卻直接將生日日期"1991-04-14"展現(xiàn)出來了.
仔細(xì)看代碼, 沒發(fā)現(xiàn)什么問題:

+ (NSString *)ageFromBirthday:(NSString *)birthday
{
    if (birthday == nil) return NSLocalizedString(@"is_not_set", nil);
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM-dd"];
    
    NSDate *destDate = [dateFormatter dateFromString:birthday];
    if (destDate == nil) 
    {
        return birthday;
    }
    NSDate *now = [NSDate date];
    NSDateComponents* ageComponents = [[NSCalendar currentCalendar]
                                       components:NSCalendarUnitYear
                                       fromDate:destDate
                                       toDate:now
                                       options:0];
    NSInteger age = [ageComponents year];
    
    return [NSString stringWithFormat:@"%ld",age];

}

但是就是在日期是"1991-04-14"時(shí), destDate = nil.
然后將代碼中birthday寫死, 換成其他日期, 比如"1991-04-15" 之類的, 發(fā)現(xiàn)沒問題.
于是單純的以為iOS系統(tǒng)在處理這個(gè)日期的時(shí)候出了bug, 還特意去網(wǎng)上搜了一下, 這天到底發(fā)生了什么事情, 是不是蘋果公司那個(gè)工程師的特殊日子.
沒有什么結(jié)果. 倒是發(fā)現(xiàn)也有人恰好碰到這個(gè)靈異事件.

于是單純以為hardCode這個(gè)日期就行了啊! 然后同事發(fā)現(xiàn)了這個(gè). 于是我覺得, 自己真的是太天真太想當(dāng)然了. 應(yīng)該搜索NSDateFormatter return nil啊! 果然SO上還是有解釋.

于是, 就這么干了:

+ (NSString *)ageFromBirthday:(NSString *)birthday
{
    if (birthday == nil) return NSLocalizedString(@"is_not_set", nil);
    
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM-dd"];
    [dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];
    [dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"]];
    
    NSDate *destDate = [dateFormatter dateFromString:birthday];
    
    NSDate *now = [NSDate date];
    if (destDate == nil) // 如果這樣還是解析為空,且后臺(tái)返回格式不是"yyyy-MM-DD",就返回默認(rèn)值 18 吧
    {
        NSArray *subStrings = [birthday componentsSeparatedByString:@"-"];
        if (subStrings.count == 3)
        {
            // 拿到當(dāng)前的年份
            NSCalendar *calendar = [NSCalendar currentCalendar];
            NSUInteger unitFlags = NSCalendarUnitYear;
            NSDateComponents *dateComponent = [calendar components:unitFlags fromDate:now];
            NSInteger year = [dateComponent year];
            NSInteger resultAge = year - [subStrings[0] integerValue];
            return [NSString stringWithFormat:@"%ld",resultAge];
        }
        return @"18";
    }
    NSDateComponents* ageComponents = [[NSCalendar currentCalendar]
                                       components:NSCalendarUnitYear
                                       fromDate:destDate
                                       toDate:now
                                       options:0];
    NSInteger age = [ageComponents year];
    
    return [NSString stringWithFormat:@"%ld",age];
}

期間因馬虎大意寫錯(cuò)好幾次,也是蛋碎.