基本上,就像标题说的那样。我想知道如何添加1天的NSDate。
如果它是:
21st February 2011
它将变成:
22nd February 2011
或者如果它是:
31st December 2011
它将变成:
1st January 2012.
基本上,就像标题说的那样。我想知道如何添加1天的NSDate。
如果它是:
21st February 2011
它将变成:
22nd February 2011
或者如果它是:
31st December 2011
它将变成:
1st January 2012.
当前回答
斯威夫特4.0
extension Date {
func add(_ unit: Calendar.Component, value: Int) -> Date? {
return Calendar.current.date(byAdding: unit, value: value, to: self)
}
}
使用
date.add(.day, 3)! // adds 3 days
date.add(.day, -14)! // subtracts 14 days
注意:如果你不知道为什么代码行以感叹号结尾,可以在谷歌上查找“Swift optional”。
其他回答
斯威夫特2.0
let today = NSDate()
let calendar = NSCalendar.currentCalendar()
let tomorrow = calendar.dateByAddingUnit(.Day, value: 1, toDate: today, options: NSCalendarOptions.MatchFirst)
在Swift 4或Swift 5中,你可以使用like bellow:
let date = Date()
let yesterday = Calendar.current.date(byAdding: .day, value: -1, to: date)
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let yesterday_date = dateFormatter.string(from: yesterday!)
print("yesterday->",yesterday_date)
输出:
Current date: 2020-03-02
yesterday date: 2020-03-01
斯威夫特5
let today = Date()
let nextDate = Calendar.current.date(byAdding: .day, value: 1, to: today)
objective - c
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
// now build a NSDate object for the next day
NSDateComponents *offsetComponents = [[NSDateComponents alloc] init];
[offsetComponents setDay:1];
NSDate *nextDate = [gregorian dateByAddingComponents:offsetComponents toDate: [NSDate date] options:0];
简单的Swift扩展昨天和明天从任何日期:
extension Date {
var previousDay: Date {
Calendar.current.date(byAdding: DateComponents(day:-1), to: self)!
}
var nextDay: Date {
Calendar.current.date(byAdding: DateComponents(day:+1), to: self)!
}
}
我在这里根据问题中的建议强制展开可选选项: 何时dateByAddingComponents:toDate:options返回nil?
NSDate *now = [NSDate date];
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit fromDate:now];
NSDate *startDate = [calendar dateFromComponents:components];
NSLog(@"StartDate = %@", startDate);
components.day += 1;
NSDate *endDate = [calendar dateFromComponents:components];
NSLog(@"EndDate = %@", endDate);