[英]Convert NSDate to NSString
如何将NSDate
转换为NSString
以便仅将@"yyyy"格式的年份输出到字符串?
How about...怎么样...
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy"];
//Optionally for time zone conversions
[formatter setTimeZone:[NSTimeZone timeZoneWithName:@"..."]];
NSString *stringFromDate = [formatter stringFromDate:myNSDateInstance];
//unless ARC is active
[formatter release];
Swift 4.2 :斯威夫特 4.2:
func stringFromDate(_ date: Date) -> String {
let formatter = DateFormatter()
formatter.dateFormat = "dd MMM yyyy HH:mm" //yyyy
return formatter.string(from: date)
}
I don't know how we all missed this: localizedStringFromDate:dateStyle:timeStyle:我不知道我们怎么都错过了这个: localizedStringFromDate:dateStyle:timeStyle:
NSString *dateString = [NSDateFormatter localizedStringFromDate:[NSDate date]
dateStyle:NSDateFormatterShortStyle
timeStyle:NSDateFormatterFullStyle];
NSLog(@"%@",dateString);
outputs '13/06/12 00:22:39 GMT+03:00'输出 '13/06/12 00:22:39 GMT+03:00'
Hope to add more value by providing the normal formatter including the year, month and day with the time.希望通过提供包括年、月和日在内的普通格式化程序来增加更多的价值。 You can use this formatter for more than just a year您可以使用此格式化程序超过一年
[dateFormat setDateFormat: @"yyyy-MM-dd HH:mm:ss zzz"];
there are a number of NSDate
helpers on the web, I tend to use:网络上有许多NSDate
助手,我倾向于使用:
https://github.com/billymeltdown/nsdate-helper/ https://github.com/billymeltdown/nsdate-helper/
Readme extract below:自述文件摘录如下:
NSString *displayString = [NSDate stringForDisplayFromDate:date];
This produces the following kinds of output:这会产生以下类型的输出:
‘3:42 AM’ – if the date is after midnight today
‘Tuesday’ – if the date is within the last seven days
‘Mar 1’ – if the date is within the current calendar year
‘Mar 1, 2008’ – else ;-)
In Swift:在斯威夫特:
var formatter = NSDateFormatter()
formatter.dateFormat = "yyyy"
var dateString = formatter.stringFromDate(YourNSDateInstanceHERE)
NSDateFormatter *dateformate=[[NSDateFormatter alloc]init];
[dateformate setDateFormat:@"yyyy"]; // Date formater
NSString *date = [dateformate stringFromDate:[NSDate date]]; // Convert date to string
NSLog(@"date :%@",date);
+(NSString*)date2str:(NSDate*)myNSDateInstance onlyDate:(BOOL)onlyDate{
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
if (onlyDate) {
[formatter setDateFormat:@"yyyy-MM-dd"];
}else{
[formatter setDateFormat: @"yyyy-MM-dd HH:mm:ss"];
}
//Optionally for time zone conversions
// [formatter setTimeZone:[NSTimeZone timeZoneWithName:@"..."]];
NSString *stringFromDate = [formatter stringFromDate:myNSDateInstance];
return stringFromDate;
}
+(NSDate*)str2date:(NSString*)dateStr{
if ([dateStr isKindOfClass:[NSDate class]]) {
return (NSDate*)dateStr;
}
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"yyyy-MM-dd"];
NSDate *date = [dateFormat dateFromString:dateStr];
return date;
}
Just add this extension:只需添加此扩展名:
extension NSDate {
var stringValue: String {
let formatter = NSDateFormatter()
formatter.dateFormat = "yourDateFormat"
return formatter.stringFromDate(self)
}
}
If you don't have NSDate
-descriptionWithCalendarFormat:timeZone:locale:
available (I don't believe iPhone/Cocoa Touch includes this) you may need to use strftime and monkey around with some C-style strings.如果你没有NSDate
-descriptionWithCalendarFormat:timeZone:locale:
可用(我不相信 iPhone/Cocoa Touch 包括这个)你可能需要使用 strftime 和一些 C 风格的字符串。 You can get the UNIX timestamp from an NSDate
using NSDate -timeIntervalSince1970
.您可以使用NSDate -timeIntervalSince1970
从NSDate
获取 UNIX 时间戳。
If you are on Mac OS X you can write:如果您使用的是 Mac OS X,您可以编写:
NSString* s = [[NSDate date] descriptionWithCalendarFormat:@"%Y_%m_%d_%H_%M_%S" timeZone:nil locale:nil];
However this is not available on iOS.但是,这在 iOS 上不可用。
swift 4 answer迅速 4 个回答
static let dateformat: String = "yyyy-MM-dd'T'HH:mm:ss"
public static func stringTodate(strDate : String) -> Date
{
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = dateformat
let date = dateFormatter.date(from: strDate)
return date!
}
public static func dateToString(inputdate : Date) -> String
{
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = dateformat
return formatter.string(from: inputdate)
}
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay) fromDate:myNSDateInstance];
NSInteger year = [components year];
// NSInteger month = [components month];
NSString *yearStr = [NSString stringWithFormat:@"%ld", year];
Define your own utility for format your date required date format for eg.定义您自己的实用程序来格式化您的日期所需的日期格式,例如。
NSString * stringFromDate(NSDate *date)
{ NSDateFormatter *formatter
[[NSDateFormatter alloc] init];
[formatter setDateFormat:@"MM ∕ dd ∕ yyyy, hh꞉mm a"];
return [formatter stringFromDate:date];
}
It's swift format :这是快速格式:
func dateFormatterWithCalendar(calndarIdentifier: Calendar.Identifier, dateFormat: String) -> DateFormatter {
let formatter = DateFormatter()
formatter.calendar = Calendar(identifier: calndarIdentifier)
formatter.dateFormat = dateFormat
return formatter
}
//Usage
let date = Date()
let fotmatter = dateFormatterWithCalendar(calndarIdentifier: .gregorian, dateFormat: "yyyy")
let dateString = fotmatter.string(from: date)
print(dateString) //2018
#ios #swift #convertDateinString #ios #swift #convertDateinString
Simply just do like this to "convert date into string" as per format you passed:只需按照您传递的格式执行此操作即可“将日期转换为字符串”:
let formatter = DateFormatter()
formatter.dateFormat = "dd-MM-YYYY" // pass formate here
let myString = formatter.string(from: date) // this will convert Date in String
Note: You can specify different formats such like "yyyy-MM-dd"
, "yyyy"
, "MM"
etc...注意:您可以指定不同的格式,例如"yyyy-MM-dd"
、 "yyyy"
、 "MM"
等...
iOS 15 now supports calling .formatted
on Date
objects directly without an explicit DateFormatter
. iOS 15 现在支持在没有显式DateFormatter
情况下直接在Date
对象上调用.formatted
。
date.formatted() // 6/8/2021, 7:30 PM
date.formatted(date: .omitted, time: .complete) // 19:30
date.formatted(date: .omitted, time: .standard) // 07:30 PM
date.formatted(date: .omitted, time: .shortened) // 7:30 PM
date.formatted(date: .omitted, time: .omitted)
// We can also specify each DateComponent separately by chaining modifiers.
date.formatted(.dateTime.weekday(.wide).day().month().hour().minute())
// Tuesday, Jun 8, 7:30 pm
// Answer to specific question
date.formatted(.dateTime.year())
extension
to have clear code使用extension
有清晰的代码You can write an extension to convert any Date
object to any desired calendar and any format您可以编写一个扩展来将任何Date
对象转换为任何所需的日历和任何格式
extension Date{
func asString(format: String = "yy/MM/dd HH:mm",
for identifier: Calendar.Identifier = .persian) -> String {
let formatter = DateFormatter()
formatter.calendar = Calendar(identifier: identifier)
formatter.dateFormat = format
return formatter.string(from: self)
}
}
Then use it like this:然后像这样使用它:
let now = Date()
print(now.asString()) // prints -> 00/04/18 20:25
print(now.asString(format: "yyyy/MM/dd")) // prints -> 1400/04/18
print(now.asString(format: "MM/dd", for: .gregorian)) // prints -> 07/09
To learn how to specify your desired format string take a look at this link .要了解如何指定所需的格式字符串,请查看此链接。
For a complete reference on how to format dates see Apple 's official Date Formatting Guide here .有关如何格式化日期的完整参考,请参阅此处的Apple官方日期格式化指南。
for Objective-C:对于 Objective-C:
NSDate *date = [NSDate dateWithTimeIntervalSinceNow:0];
NSDateFormatter *formatter = [NSDateFormatter new];
formatter.dateFormat = @"yyyy";
NSString *dateString = [formatter stringFromDate:date];
for Swift:对于斯威夫特:
let now = Date()
let formatter = DateFormatter()
formatter.dateFormat = "yyyy"
let dateString = formatter.string(from: now)
That's a good website for nsdateformatter .You can preview date strings with different DateFormatter
in different local.这是一个很好的nsdateformatter网站。您可以在不同的本地使用不同的DateFormatter
预览日期字符串。
Simple way to use C# styled way to convert Date to String.使用 C# 样式方式将日期转换为字符串的简单方法。
usage:用法:
let a = time.asString()
// 1990-03-25
let b = time.asString("MM ∕ dd ∕ yyyy, hh꞉mm a")
// 03 / 25 / 1990, 10:33 PM
extensions:扩展:
extension Date {
func asString(_ template: String? = nil) -> String {
if let template = template {
let df = DateFormatter.with(template: template)
return df.string(from: self)
}
else {
return globalDateFormatter.string(from: self)
}
}
}
// Here you can set default template for DateFormatter
public let globalDateFormatter: DateFormatter = DateFormatter.with(template: "y-M-d")
public extension DateFormatter {
static func with(template: String ) -> DateFormatter {
let df = DateFormatter()
df.dateFormat = template
return df
}
}
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