检查 NSDate 是否为 Monday/Tues/etc

Question

我有一个 iOS 应用程序需要根据当天设置几个不同的日期标签。我正在使用 NSDate 和 NSDateFormatter 来执行此操作。但是有一些我不确定的事情：如果用户有一个 iOS 设备并且他们的 language/localisation 设置为英语以外的其他东西，那么我的 if 语句会检查它当前是否 "Monday" 或 "Tuesday"，停止工作？

这是我的代码：

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = @"yyyyMMdd";
NSDate *date = [NSDate date];

dateFormatter.dateFormat = @"EEEE";
NSString *dayString = [[dateFormatter stringFromDate:date] capitalizedString];
NSLog(@"Day: %@", dayString);


if ([dayString isEqualToString:@"Monday"]) {

}

else if ([dayString isEqualToString:@"Tuesday"]) {

}

else if ([dayString isEqualToString:@"Wednesday"]) {

}

else if ([dayString isEqualToString:@"Thursday"]) {

}

else if ([dayString isEqualToString:@"Friday"]) {

}

else if ([dayString isEqualToString:@"Saturday"]) {

}

else if ([dayString isEqualToString:@"Sunday"]) {

}

Answer 1

您可以使用以下程序。

NSDateComponents *component = [[NSCalendar currentCalendar] components:NSCalendarUnitWeekday fromDate:[NSDate date]];

switch ([component weekday]) {
    case 1:
        //Sunday
        break;
    case 2:
        //Monday
        break;
    ...
    case 7:
        //Saturday
        break;
    default:
        break;
}

Answer 2

虽然使用 NSDateComponents 的答案是最佳选择，但使用工作日字符串的另一种可能性是：

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = @"EEEE";
NSDate *date = [NSDate date];
NSString *dayString = [dateFormatter stringFromDate:date];

NSInteger weekdayNum = [[dateFormatter weekdaySymbols] indexOfObject:dayString];
switch (weekdayNum) {
    case 0:
        //Sunday
        break;
    case 1:
        //Monday
        break;
    ...
    case 6:
        //Saturday
        break;
    default:
        break;
}

Answer 3

你Swift，你可以这样做：

let calendar: Calendar = Calendar.current
let isMonday = calendar.component(Calendar.Component.weekday, from: self) == 2

或者您可以使用此 Date 扩展来获取日期的星期几：

extension Date {

    enum WeekDay: Int {
        case sunday = 1
        case monday
        case tuesday
        case wednesday
        case thursday
        case friday
        case saturday
    }

    func getWeekDay() -> WeekDay {
        let calendar = Calendar.current
        let weekDay = calendar.component(Calendar.Component.weekday, from: self)
        return WeekDay(rawValue: weekDay)!
    }
}

let date = Date()
date.getWeekDay()

检查 NSDate 是否为 Monday/Tues/etc

Check whether NSDate is Monday/Tues/etc

ios

objective-c

cocoa-touch

date

nsdate