Hoe bereken ek iemand se ouderdom in C#?
https://stackoverflow.com/questions/9
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Gegewe 'n DateTime wat 'n persoon se verjaardag verteenwoordig, hoe bereken ek hul ouderdom in jare?
Oplossing
'n Maklik verstaanbare en eenvoudige oplossing.
// Save today's date.
var today = DateTime.Today;
// Calculate the age.
var age = today.Year - birthdate.Year;
// Go back to the year the person was born in case of a leap year
if (birthdate.Date > today.AddYears(-age)) age--;
Dit neem egter aan dat jy op soek is na die westers idee van ouderdom en nie gebruik nie Oos-Asiatiese afrekening.
Ander wenke
Dit is 'n vreemde manier om dit te doen, maar as jy die datum formateer na yyyymmdd en trek die geboortedatum van die huidige datum af en los dan die laaste 4 syfers wat jy die ouderdom het :)
Ek ken nie C# nie, maar ek glo dit sal in enige taal werk.
20080814 - 19800703 = 280111
Los die laaste 4 syfers = 28.
C# kode:
int now = int.Parse(DateTime.Now.ToString("yyyyMMdd"));
int dob = int.Parse(dateOfBirth.ToString("yyyyMMdd"));
int age = (now - dob) / 10000;
Of alternatiewelik sonder al die tipe omskakeling in die vorm van 'n uitbreidingsmetode.Foutkontrolering is weggelaat:
public static Int32 GetAge(this DateTime dateOfBirth)
{
var today = DateTime.Today;
var a = (today.Year * 100 + today.Month) * 100 + today.Day;
var b = (dateOfBirth.Year * 100 + dateOfBirth.Month) * 100 + dateOfBirth.Day;
return (a - b) / 10000;
}
Ek weet nie hoe die verkeerde oplossing aanvaar kan word nie.Die korrekte C#-brokkie is deur Michael Stum geskryf
Hier is 'n toetsbrokkie:
DateTime bDay = new DateTime(2000, 2, 29);
DateTime now = new DateTime(2009, 2, 28);
MessageBox.Show(string.Format("Test {0} {1} {2}",
CalculateAgeWrong1(bDay, now), // outputs 9
CalculateAgeWrong2(bDay, now), // outputs 9
CalculateAgeCorrect(bDay, now))); // outputs 8
Hier het jy die metodes:
public int CalculateAgeWrong1(DateTime birthDate, DateTime now)
{
return new DateTime(now.Subtract(birthDate).Ticks).Year - 1;
}
public int CalculateAgeWrong2(DateTime birthDate, DateTime now)
{
int age = now.Year - birthDate.Year;
if (now < birthDate.AddYears(age))
age--;
return age;
}
public int CalculateAgeCorrect(DateTime birthDate, DateTime now)
{
int age = now.Year - birthDate.Year;
if (now.Month < birthDate.Month || (now.Month == birthDate.Month && now.Day < birthDate.Day))
age--;
return age;
}
Ek dink nie een van die antwoorde tot dusver maak voorsiening vir kulture wat ouderdom anders bereken nie.Sien bv. Oos-Asiatiese ouderdomsberekening teenoor dié in die Weste.
Enige werklike antwoord moet lokalisering insluit.Die Strategie patroon sal waarskynlik in hierdie voorbeeld in orde wees.
Die eenvoudige antwoord hierop is om aansoek te doen AddYears soos hieronder getoon, want dit is die enigste inheemse metode om jare by die 29ste Feb.van skrikkeljare en verkry die korrekte resultaat van die 28ste Feb.vir gewone jare.
Sommige voel dat 1 Mrt.is die verjaarsdag van leaplings, maar nie .Net of enige amptelike reël ondersteun dit nie, en algemene logika verduidelik ook nie hoekom sommige wat in Februarie gebore is, 75% van hul verjaarsdae oor nog 'n maand moet hê nie.
Verder leen 'n Ouderdomsmetode hom om bygevoeg te word as 'n uitbreiding by DateTime.Hierdeur kan jy die ouderdom op die eenvoudigste moontlike manier verkry:
- Lys item
int ouderdom = geboortedatum.Age();
public static class DateTimeExtensions
{
/// <summary>
/// Calculates the age in years of the current System.DateTime object today.
/// </summary>
/// <param name="birthDate">The date of birth</param>
/// <returns>Age in years today. 0 is returned for a future date of birth.</returns>
public static int Age(this DateTime birthDate)
{
return Age(birthDate, DateTime.Today);
}
/// <summary>
/// Calculates the age in years of the current System.DateTime object on a later date.
/// </summary>
/// <param name="birthDate">The date of birth</param>
/// <param name="laterDate">The date on which to calculate the age.</param>
/// <returns>Age in years on a later day. 0 is returned as minimum.</returns>
public static int Age(this DateTime birthDate, DateTime laterDate)
{
int age;
age = laterDate.Year - birthDate.Year;
if (age > 0)
{
age -= Convert.ToInt32(laterDate.Date < birthDate.Date.AddYears(age));
}
else
{
age = 0;
}
return age;
}
}
Voer nou hierdie toets uit:
class Program
{
static void Main(string[] args)
{
RunTest();
}
private static void RunTest()
{
DateTime birthDate = new DateTime(2000, 2, 28);
DateTime laterDate = new DateTime(2011, 2, 27);
string iso = "yyyy-MM-dd";
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
Console.WriteLine("Birth date: " + birthDate.AddDays(i).ToString(iso) + " Later date: " + laterDate.AddDays(j).ToString(iso) + " Age: " + birthDate.AddDays(i).Age(laterDate.AddDays(j)).ToString());
}
}
Console.ReadKey();
}
}
Die kritieke datumvoorbeeld is die volgende:
Geboortedatum:2000-02-29 Latere datum:2011-02-28 Ouderdom:11
Uitset:
{
Birth date: 2000-02-28 Later date: 2011-02-27 Age: 10
Birth date: 2000-02-28 Later date: 2011-02-28 Age: 11
Birth date: 2000-02-28 Later date: 2011-03-01 Age: 11
Birth date: 2000-02-29 Later date: 2011-02-27 Age: 10
Birth date: 2000-02-29 Later date: 2011-02-28 Age: 11
Birth date: 2000-02-29 Later date: 2011-03-01 Age: 11
Birth date: 2000-03-01 Later date: 2011-02-27 Age: 10
Birth date: 2000-03-01 Later date: 2011-02-28 Age: 10
Birth date: 2000-03-01 Later date: 2011-03-01 Age: 11
}
En vir die latere datum 2012-02-28:
{
Birth date: 2000-02-28 Later date: 2012-02-28 Age: 12
Birth date: 2000-02-28 Later date: 2012-02-29 Age: 12
Birth date: 2000-02-28 Later date: 2012-03-01 Age: 12
Birth date: 2000-02-29 Later date: 2012-02-28 Age: 11
Birth date: 2000-02-29 Later date: 2012-02-29 Age: 12
Birth date: 2000-02-29 Later date: 2012-03-01 Age: 12
Birth date: 2000-03-01 Later date: 2012-02-28 Age: 11
Birth date: 2000-03-01 Later date: 2012-02-29 Age: 11
Birth date: 2000-03-01 Later date: 2012-03-01 Age: 12
}
My voorstel
int age = (int) ((DateTime.Now - bday).TotalDays/365.242199);
Dit lyk asof die jaar op die regte datum verander.(Ek het getoets tot op ouderdom 107)
Nog 'n funksie, nie deur my nie, maar gevind op die web en het dit 'n bietjie verfyn:
public static int GetAge(DateTime birthDate)
{
DateTime n = DateTime.Now; // To avoid a race condition around midnight
int age = n.Year - birthDate.Year;
if (n.Month < birthDate.Month || (n.Month == birthDate.Month && n.Day < birthDate.Day))
age--;
return age;
}
Net twee dinge wat in my gedagtes opkom:Wat van mense van lande wat nie die Gregoriaanse kalender gebruik nie?DateTime.Now is in die bediener-spesifieke kultuur dink ek.Ek het absoluut 0 kennis oor om werklik met Asiatiese kalenders te werk en ek weet nie of daar 'n maklike manier is om datums tussen kalenders om te skakel nie, maar vir ingeval jy wonder oor daardie Chinese ouens van die jaar 4660 :-)
2 Hoofprobleme om op te los is:
1.Bereken die presiese ouderdom - in jare, maande, dae, ens.
2.Bereken Algemeen waargenome ouderdom - mense gee gewoonlik nie om hoe oud hulle presies is nie, hulle gee net om wanneer hulle verjaarsdag in die huidige jaar is.
Oplossing vir 1 is voor die hand liggend:
DateTime birth = DateTime.Parse("1.1.2000");
DateTime today = DateTime.Today; //we usually don't care about birth time
TimeSpan age = today - birth; //.NET FCL should guarantee this as precise
double ageInDays = age.TotalDays; //total number of days ... also precise
double daysInYear = 365.2425; //statistical value for 400 years
double ageInYears = ageInDays / daysInYear; //can be shifted ... not so precise
Oplossing vir 2 is die een wat nie so presies is in die bepaling van totale ouderdom nie, maar as presies deur mense ervaar word.Mense gebruik dit ook gewoonlik wanneer hulle hul ouderdom "handmatig" bereken:
DateTime birth = DateTime.Parse("1.1.2000");
DateTime today = DateTime.Today;
int age = today.Year - birth.Year; //people perceive their age in years
if (today.Month < birth.Month ||
((today.Month == birth.Month) && (today.Day < birth.Day)))
{
age--; //birthday in current year not yet reached, we are 1 year younger ;)
//+ no birthday for 29.2. guys ... sorry, just wrong date for birth
}
Notas tot 2.:
- Dit is my voorkeuroplossing
- Ons kan nie DateTime.DayOfYear of TimeSpans gebruik nie, aangesien dit die aantal dae in skrikkeljare verskuif
- Ek het 'n bietjie meer reëls daar geplaas vir leesbaarheid
Net nog 'n nota ...Ek sal 2 statiese oorlaaide metodes daarvoor skep, een vir universele gebruik, tweede vir gebruiksvriendelikheid:
public static int GetAge(DateTime bithDay, DateTime today)
{
//chosen solution method body
}
public static int GetAge(DateTime birthDay)
{
return GetAge(birthDay, DateTime.Now);
}
Ek is laat vir die partytjie, maar hier is 'n eenlyn:
int age = new DateTime(DateTime.Now.Subtract(birthday).Ticks).Year-1;
Dit is die weergawe wat ons hier gebruik.Dit werk, en dit is redelik eenvoudig.Dit is dieselfde idee as Jeff s'n, maar ek dink dit is 'n bietjie duideliker, want dit skei die logika om een af te trek, so dit is 'n bietjie makliker om te verstaan.
public static int GetAge(this DateTime dateOfBirth, DateTime dateAsAt)
{
return dateAsAt.Year - dateOfBirth.Year - (dateOfBirth.DayOfYear < dateAsAt.DayOfYear ? 0 : 1);
}
Jy kan die drieledige operateur uitbrei om dit nog duideliker te maak, as jy dink daardie soort ding is onduidelik.
Dit word natuurlik gedoen as 'n uitbreidingsmetode op DateTime, maar duidelik kan jy daardie een reël kode wat die werk doen gryp en dit enige plek plaas.Hier het ons nog 'n oorlading van die Uitbreidingsmetode wat ingaan DateTime.Now, net vir volledigheid.
Die beste manier waarvan ek weet as gevolg van skrikkeljare en alles is:
DateTime birthDate = new DateTime(2000,3,1);
int age = (int)Math.Floor((DateTime.Now - birthDate).TotalDays / 365.25D);
Hoop dit help.
Ek gebruik hierdie:
public static class DateTimeExtensions
{
public static int Age(this DateTime birthDate)
{
return Age(birthDate, DateTime.Now);
}
public static int Age(this DateTime birthDate, DateTime offsetDate)
{
int result=0;
result = offsetDate.Year - birthDate.Year;
if (offsetDate.DayOfYear < birthDate.DayOfYear)
{
result--;
}
return result;
}
}
Dit gee "meer detail" aan hierdie vraag.Miskien is dit waarna jy soek
DateTime birth = new DateTime(1974, 8, 29);
DateTime today = DateTime.Now;
TimeSpan span = today - birth;
DateTime age = DateTime.MinValue + span;
// Make adjustment due to MinValue equalling 1/1/1
int years = age.Year - 1;
int months = age.Month - 1;
int days = age.Day - 1;
// Print out not only how many years old they are but give months and days as well
Console.Write("{0} years, {1} months, {2} days", years, months, days);
Ek het 'n SQL Server-gebruikergedefinieerde funksie geskep om iemand se ouderdom te bereken, gegewe hul geboortedatum.Dit is nuttig wanneer jy dit nodig het as deel van 'n navraag:
using System;
using System.Data;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
public partial class UserDefinedFunctions
{
[SqlFunction(DataAccess = DataAccessKind.Read)]
public static SqlInt32 CalculateAge(string strBirthDate)
{
DateTime dtBirthDate = new DateTime();
dtBirthDate = Convert.ToDateTime(strBirthDate);
DateTime dtToday = DateTime.Now;
// get the difference in years
int years = dtToday.Year - dtBirthDate.Year;
// subtract another year if we're before the
// birth day in the current year
if (dtToday.Month < dtBirthDate.Month || (dtToday.Month == dtBirthDate.Month && dtToday.Day < dtBirthDate.Day))
years=years-1;
int intCustomerAge = years;
return intCustomerAge;
}
};
Ek het 'n geruime tyd hieraan gewerk en dit uitgedink om iemand se ouderdom in jare, maande en dae te bereken.Ek het getoets teen die probleem van 29 Februarie en skrikkeljare en dit lyk of dit werk, ek sal enige terugvoer waardeer:
public void LoopAge(DateTime myDOB, DateTime FutureDate)
{
int years = 0;
int months = 0;
int days = 0;
DateTime tmpMyDOB = new DateTime(myDOB.Year, myDOB.Month, 1);
DateTime tmpFutureDate = new DateTime(FutureDate.Year, FutureDate.Month, 1);
while (tmpMyDOB.AddYears(years).AddMonths(months) < tmpFutureDate)
{
months++;
if (months > 12)
{
years++;
months = months - 12;
}
}
if (FutureDate.Day >= myDOB.Day)
{
days = days + FutureDate.Day - myDOB.Day;
}
else
{
months--;
if (months < 0)
{
years--;
months = months + 12;
}
days +=
DateTime.DaysInMonth(
FutureDate.AddMonths(-1).Year, FutureDate.AddMonths(-1).Month
) + FutureDate.Day - myDOB.Day;
}
//add an extra day if the dob is a leap day
if (DateTime.IsLeapYear(myDOB.Year) && myDOB.Month == 2 && myDOB.Day == 29)
{
//but only if the future date is less than 1st March
if (FutureDate >= new DateTime(FutureDate.Year, 3, 1))
days++;
}
}
Hier is nog 'n antwoord:
public static int AgeInYears(DateTime birthday, DateTime today)
{
return ((today.Year - birthday.Year) * 372 + (today.Month - birthday.Month) * 31 + (today.Day - birthday.Day)) / 372;
}
Dit is omvattend eenheid getoets.Dit lyk 'n bietjie "magic".Die getal 372 is die aantal dae wat daar in 'n jaar sou wees as elke maand 31 dae gehad het.
Die verduideliking van hoekom dit werk (van hier af opgelig) is:
Kom ons stel
Yn = DateTime.Now.Year, Yb = birthday.Year, Mn = DateTime.Now.Month, Mb = birthday.Month, Dn = DateTime.Now.Day, Db = birthday.Day
age = Yn - Yb + (31*(Mn - Mb) + (Dn - Db)) / 372Ons weet dat wat ons nodig het, is óf
Yn-Ybindien die datum reeds bereik is,Yn-Yb-1as dit nie het nie.a) Indien
Mn<Mb, ons het-341 <= 31*(Mn-Mb) <= -31 and -30 <= Dn-Db <= 30
-371 <= 31*(Mn - Mb) + (Dn - Db) <= -1Met heelgetalverdeling
(31*(Mn - Mb) + (Dn - Db)) / 372 = -1b) Indien
Mn=MbenDn<Db, ons het31*(Mn - Mb) = 0 and -30 <= Dn-Db <= -1Met heelgetalverdeling, weer
(31*(Mn - Mb) + (Dn - Db)) / 372 = -1c) Indien
Mn>Mb, ons het31 <= 31*(Mn-Mb) <= 341 and -30 <= Dn-Db <= 30
1 <= 31*(Mn - Mb) + (Dn - Db) <= 371Met heelgetalverdeling
(31*(Mn - Mb) + (Dn - Db)) / 372 = 0d) Indien
Mn=MbenDn>Db, ons het31*(Mn - Mb) = 0 and 1 <= Dn-Db <= 30Met heelgetalverdeling, weer
(31*(Mn - Mb) + (Dn - Db)) / 372 = 0e) Indien
Mn=MbenDn=Db, ons het31*(Mn - Mb) + Dn-Db = 0en dus
(31*(Mn - Mb) + (Dn - Db)) / 372 = 0
Moet ons mense wat kleiner as 1 jaar is, in ag neem?as Chinese kultuur beskryf ons klein babas se ouderdom as 2 maande of 4 weke.
Hieronder is my implementering, dit is nie so eenvoudig soos wat ek my voorgestel het nie, veral om te gaan met datum soos 28/2.
public static string HowOld(DateTime birthday, DateTime now)
{
if (now < birthday)
throw new ArgumentOutOfRangeException("birthday must be less than now.");
TimeSpan diff = now - birthday;
int diffDays = (int)diff.TotalDays;
if (diffDays > 7)//year, month and week
{
int age = now.Year - birthday.Year;
if (birthday > now.AddYears(-age))
age--;
if (age > 0)
{
return age + (age > 1 ? " years" : " year");
}
else
{// month and week
DateTime d = birthday;
int diffMonth = 1;
while (d.AddMonths(diffMonth) <= now)
{
diffMonth++;
}
age = diffMonth-1;
if (age == 1 && d.Day > now.Day)
age--;
if (age > 0)
{
return age + (age > 1 ? " months" : " month");
}
else
{
age = diffDays / 7;
return age + (age > 1 ? " weeks" : " week");
}
}
}
else if (diffDays > 0)
{
int age = diffDays;
return age + (age > 1 ? " days" : " day");
}
else
{
int age = diffDays;
return "just born";
}
}
Hierdie implementering het onder toetsgevalle geslaag.
[TestMethod]
public void TestAge()
{
string age = HowOld(new DateTime(2011, 1, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("1 year", age);
age = HowOld(new DateTime(2011, 11, 30), new DateTime(2012, 11, 30));
Assert.AreEqual("1 year", age);
age = HowOld(new DateTime(2001, 1, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("11 years", age);
age = HowOld(new DateTime(2012, 1, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("10 months", age);
age = HowOld(new DateTime(2011, 12, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("11 months", age);
age = HowOld(new DateTime(2012, 10, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("1 month", age);
age = HowOld(new DateTime(2008, 2, 28), new DateTime(2009, 2, 28));
Assert.AreEqual("1 year", age);
age = HowOld(new DateTime(2008, 3, 28), new DateTime(2009, 2, 28));
Assert.AreEqual("11 months", age);
age = HowOld(new DateTime(2008, 3, 28), new DateTime(2009, 3, 28));
Assert.AreEqual("1 year", age);
age = HowOld(new DateTime(2009, 1, 28), new DateTime(2009, 2, 28));
Assert.AreEqual("1 month", age);
age = HowOld(new DateTime(2009, 2, 1), new DateTime(2009, 3, 1));
Assert.AreEqual("1 month", age);
// NOTE.
// new DateTime(2008, 1, 31).AddMonths(1) == new DateTime(2009, 2, 28);
// new DateTime(2008, 1, 28).AddMonths(1) == new DateTime(2009, 2, 28);
age = HowOld(new DateTime(2009, 1, 31), new DateTime(2009, 2, 28));
Assert.AreEqual("4 weeks", age);
age = HowOld(new DateTime(2009, 2, 1), new DateTime(2009, 2, 28));
Assert.AreEqual("3 weeks", age);
age = HowOld(new DateTime(2009, 2, 1), new DateTime(2009, 3, 1));
Assert.AreEqual("1 month", age);
age = HowOld(new DateTime(2012, 11, 5), new DateTime(2012, 11, 30));
Assert.AreEqual("3 weeks", age);
age = HowOld(new DateTime(2012, 11, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("4 weeks", age);
age = HowOld(new DateTime(2012, 11, 20), new DateTime(2012, 11, 30));
Assert.AreEqual("1 week", age);
age = HowOld(new DateTime(2012, 11, 25), new DateTime(2012, 11, 30));
Assert.AreEqual("5 days", age);
age = HowOld(new DateTime(2012, 11, 29), new DateTime(2012, 11, 30));
Assert.AreEqual("1 day", age);
age = HowOld(new DateTime(2012, 11, 30), new DateTime(2012, 11, 30));
Assert.AreEqual("just born", age);
age = HowOld(new DateTime(2000, 2, 29), new DateTime(2009, 2, 28));
Assert.AreEqual("8 years", age);
age = HowOld(new DateTime(2000, 2, 29), new DateTime(2009, 3, 1));
Assert.AreEqual("9 years", age);
Exception e = null;
try
{
age = HowOld(new DateTime(2012, 12, 1), new DateTime(2012, 11, 30));
}
catch (ArgumentOutOfRangeException ex)
{
e = ex;
}
Assert.IsTrue(e != null);
}
Hoop dit is nuttig.
Hou dit eenvoudig (en moontlik dom :)).
DateTime birth = new DateTime(1975, 09, 27, 01, 00, 00, 00);
TimeSpan ts = DateTime.Now - birth;
Console.WriteLine("You are approximately " + ts.TotalSeconds.ToString() + " seconds old.");
TimeSpan diff = DateTime.Now - birthdayDateTime;
string age = String.Format("{0:%y} years, {0:%M} months, {0:%d}, days old", diff);
Ek is nie seker hoe presies jy dit aan jou wil terugbesorg nie, so ek het net 'n leesbare string gemaak.
Die eenvoudigste manier wat ek nog ooit gevind het, is dit.Dit werk korrek vir die VSA en Wes-Europa.Kan nie met ander plekke praat nie, veral plekke soos China.4 ekstra vergelyk hoogstens na die aanvanklike berekening van ouderdom.
public int AgeInYears(DateTime birthDate, DateTime referenceDate)
{
Debug.Assert(referenceDate >= birthDate,
"birth date must be on or prior to the reference date");
DateTime birth = birthDate.Date;
DateTime reference = referenceDate.Date;
int years = (reference.Year - birth.Year);
//
// an offset of -1 is applied if the birth date has
// not yet occurred in the current year.
//
if (reference.Month > birth.Month);
else if (reference.Month < birth.Month)
--years;
else // in birth month
{
if (reference.Day < birth.Day)
--years;
}
return years ;
}
Ek het na die antwoorde hierop gekyk en opgemerk dat niemand verwys het na regulatoriese/wetlike implikasies van skrikkeldaggeboortes nie.Byvoorbeeld, per Wikipedia, as jy op 29 Februarie in verskeie jurisdiksies gebore is, verskil jou nie-skrikkeljaarverjaarsdag:
- In die Verenigde Koninkryk en Hong Kong:dit is die gewone dag van die jaar, so die volgende dag, 1 Maart is jou verjaarsdag.
- In Nieu-Seeland:dit is die vorige dag, 28 Februarie vir die doeleindes van bestuurslisensies, en 1 Maart vir ander doeleindes.
- Taiwan:dit is 28 Februarie.
En so na as wat ek kan sê, in die VSA, swyg die statute oor die saak, en laat dit oor aan die gemenereg en aan hoe verskeie regulerende liggame dinge in hul regulasies definieer.
Vir daardie doel, 'n verbetering:
public enum LeapDayRule
{
OrdinalDay = 1 ,
LastDayOfMonth = 2 ,
}
static int ComputeAgeInYears(DateTime birth, DateTime reference, LeapYearBirthdayRule ruleInEffect)
{
bool isLeapYearBirthday = CultureInfo.CurrentCulture.Calendar.IsLeapDay(birth.Year, birth.Month, birth.Day);
DateTime cutoff;
if (isLeapYearBirthday && !DateTime.IsLeapYear(reference.Year))
{
switch (ruleInEffect)
{
case LeapDayRule.OrdinalDay:
cutoff = new DateTime(reference.Year, 1, 1)
.AddDays(birth.DayOfYear - 1);
break;
case LeapDayRule.LastDayOfMonth:
cutoff = new DateTime(reference.Year, birth.Month, 1)
.AddMonths(1)
.AddDays(-1);
break;
default:
throw new InvalidOperationException();
}
}
else
{
cutoff = new DateTime(reference.Year, birth.Month, birth.Day);
}
int age = (reference.Year - birth.Year) + (reference >= cutoff ? 0 : -1);
return age < 0 ? 0 : age;
}
Daar moet kennis geneem word dat hierdie kode veronderstel:
- 'n Westerse (Europese) berekening van ouderdom, en
- 'n Kalender, soos die Gregoriaanse kalender wat 'n enkele skrikkeldag aan die einde van 'n maand invoeg.
Dit is nie 'n direkte antwoord nie, maar eerder 'n filosofiese redenasie oor die probleem wat voorhande is vanuit 'n kwasi-wetenskaplike oogpunt.
Ek sou argumenteer dat die vraag nie die eenheid of kultuur spesifiseer waarin ouderdom gemeet moet word nie, die meeste antwoorde blyk 'n heelgetal jaarlikse verteenwoordiging te aanvaar.Die SI-eenheid vir tyd is second, dus moet die korrekte generiese antwoord wees (natuurlik as genormaliseer word DateTime en hoegenaamd geen ag op relativistiese effekte nie):
var lifeInSeconds = (DateTime.Now.Ticks - then.Ticks)/TickFactor;
In die Christelike manier om ouderdom in jare te bereken:
var then = ... // Then, in this case the birthday
var now = DateTime.UtcNow;
int age = now.Year - then.Year;
if (now.AddYears(-age) < then) age--;
In finansies is daar 'n soortgelyke probleem wanneer iets bereken word waarna dikwels verwys word as die Dagtelling breuk, wat rofweg 'n aantal jare vir 'n gegewe tydperk is.En die ouderdomskwessie is regtig 'n tydmetingskwessie.
Voorbeeld vir die werklike/werklike (wat alle dae "korrek tel") konvensie:
DateTime start, end = .... // Whatever, assume start is before end
double startYearContribution = 1 - (double) start.DayOfYear / (double) (DateTime.IsLeapYear(start.Year) ? 366 : 365);
double endYearContribution = (double)end.DayOfYear / (double)(DateTime.IsLeapYear(end.Year) ? 366 : 365);
double middleContribution = (double) (end.Year - start.Year - 1);
double DCF = startYearContribution + endYearContribution + middleContribution;
Nog 'n baie algemene manier om tyd oor die algemeen te meet, is deur te "serialiseer" (die ou wat hierdie datumkonvensie genoem het, moes ernstig gesukkel het):
DateTime start, end = .... // Whatever, assume start is before end
int days = (end - start).Days;
Ek wonder hoe lank moet ons gaan voordat 'n relativistiese ouderdom in sekondes nuttiger word as die rowwe benadering van aarde-om-son-siklusse gedurende 'n mens se leeftyd tot dusver :) Of met ander woorde, wanneer 'n tydperk 'n ligging gegee moet word of 'n funksie wat beweging voorstel vir homself om geldig te wees :)
Hier is 'n oplossing.
DateTime dateOfBirth = new DateTime(2000, 4, 18);
DateTime currentDate = DateTime.Now;
int ageInYears = 0;
int ageInMonths = 0;
int ageInDays = 0;
ageInDays = currentDate.Day - dateOfBirth.Day;
ageInMonths = currentDate.Month - dateOfBirth.Month;
ageInYears = currentDate.Year - dateOfBirth.Year;
if (ageInDays < 0)
{
ageInDays += DateTime.DaysInMonth(currentDate.Year, currentDate.Month);
ageInMonths = ageInMonths--;
if (ageInMonths < 0)
{
ageInMonths += 12;
ageInYears--;
}
}
if (ageInMonths < 0)
{
ageInMonths += 12;
ageInYears--;
}
Console.WriteLine("{0}, {1}, {2}", ageInYears, ageInMonths, ageInDays);
Dit is een van die mees akkurate antwoorde wat die verjaarsdag van 29 Feb kan oplos in vergelyking met enige jaar van 28 Feb.
public int GetAge(DateTime birthDate)
{
int age = DateTime.Now.Year - birthDate.Year;
if (birthDate.DayOfYear > DateTime.Now.DayOfYear)
age--;
return age;
}
Ek het 'n pasgemaakte metode om ouderdom te bereken, plus 'n bonusbekragtigingsboodskap vir ingeval dit help:
public void GetAge(DateTime dob, DateTime now, out int years, out int months, out int days)
{
years = 0;
months = 0;
days = 0;
DateTime tmpdob = new DateTime(dob.Year, dob.Month, 1);
DateTime tmpnow = new DateTime(now.Year, now.Month, 1);
while (tmpdob.AddYears(years).AddMonths(months) < tmpnow)
{
months++;
if (months > 12)
{
years++;
months = months - 12;
}
}
if (now.Day >= dob.Day)
days = days + now.Day - dob.Day;
else
{
months--;
if (months < 0)
{
years--;
months = months + 12;
}
days += DateTime.DaysInMonth(now.AddMonths(-1).Year, now.AddMonths(-1).Month) + now.Day - dob.Day;
}
if (DateTime.IsLeapYear(dob.Year) && dob.Month == 2 && dob.Day == 29 && now >= new DateTime(now.Year, 3, 1))
days++;
}
private string ValidateDate(DateTime dob) //This method will validate the date
{
int Years = 0; int Months = 0; int Days = 0;
GetAge(dob, DateTime.Now, out Years, out Months, out Days);
if (Years < 18)
message = Years + " is too young. Please try again on your 18th birthday.";
else if (Years >= 65)
message = Years + " is too old. Date of Birth must not be 65 or older.";
else
return null; //Denotes validation passed
}
Metode-roep hier en gee datum-tyd-waarde uit (MM/dd/jjjj as bediener op VSA-lokaal gestel is).Vervang dit met enigiets 'n boodskapkas of enige houer om te vertoon:
DateTime dob = DateTime.Parse("03/10/1982");
string message = ValidateDate(dob);
lbldatemessage.Visible = !StringIsNullOrWhitespace(message);
lbldatemessage.Text = message ?? ""; //Ternary if message is null then default to empty string
Onthou dat jy die boodskap kan formateer op enige manier wat jy wil.
Wat van hierdie oplossing?
static string CalcAge(DateTime birthDay)
{
DateTime currentDate = DateTime.Now;
int approximateAge = currentDate.Year - birthDay.Year;
int daysToNextBirthDay = (birthDay.Month * 30 + birthDay.Day) -
(currentDate.Month * 30 + currentDate.Day) ;
if (approximateAge == 0 || approximateAge == 1)
{
int month = Math.Abs(daysToNextBirthDay / 30);
int days = Math.Abs(daysToNextBirthDay % 30);
if (month == 0)
return "Your age is: " + daysToNextBirthDay + " days";
return "Your age is: " + month + " months and " + days + " days"; ;
}
if (daysToNextBirthDay > 0)
return "Your age is: " + --approximateAge + " Years";
return "Your age is: " + approximateAge + " Years"; ;
}
private int GetAge(int _year, int _month, int _day
{
DateTime yourBirthDate= new DateTime(_year, _month, _day);
DateTime todaysDateTime = DateTime.Today;
int noOfYears = todaysDateTime.Year - yourBirthDate.Year;
if (DateTime.Now.Month < yourBirthDate.Month ||
(DateTime.Now.Month == yourBirthDate.Month && DateTime.Now.Day < yourBirthDate.Day))
{
noOfYears--;
}
return noOfYears;
}
Die volgende benadering (uittreksel uit Tydperiodebiblioteek vir .NET klas DateDiff) beskou die kalender van die kultuurinligting:
// ----------------------------------------------------------------------
private static int YearDiff( DateTime date1, DateTime date2 )
{
return YearDiff( date1, date2, DateTimeFormatInfo.CurrentInfo.Calendar );
} // YearDiff
// ----------------------------------------------------------------------
private static int YearDiff( DateTime date1, DateTime date2, Calendar calendar )
{
if ( date1.Equals( date2 ) )
{
return 0;
}
int year1 = calendar.GetYear( date1 );
int month1 = calendar.GetMonth( date1 );
int year2 = calendar.GetYear( date2 );
int month2 = calendar.GetMonth( date2 );
// find the the day to compare
int compareDay = date2.Day;
int compareDaysPerMonth = calendar.GetDaysInMonth( year1, month1 );
if ( compareDay > compareDaysPerMonth )
{
compareDay = compareDaysPerMonth;
}
// build the compare date
DateTime compareDate = new DateTime( year1, month2, compareDay,
date2.Hour, date2.Minute, date2.Second, date2.Millisecond );
if ( date2 > date1 )
{
if ( compareDate < date1 )
{
compareDate = compareDate.AddYears( 1 );
}
}
else
{
if ( compareDate > date1 )
{
compareDate = compareDate.AddYears( -1 );
}
}
return year2 - calendar.GetYear( compareDate );
} // YearDiff
Gebruik:
// ----------------------------------------------------------------------
public void CalculateAgeSamples()
{
PrintAge( new DateTime( 2000, 02, 29 ), new DateTime( 2009, 02, 28 ) );
// > Birthdate=29.02.2000, Age at 28.02.2009 is 8 years
PrintAge( new DateTime( 2000, 02, 29 ), new DateTime( 2012, 02, 28 ) );
// > Birthdate=29.02.2000, Age at 28.02.2012 is 11 years
} // CalculateAgeSamples
// ----------------------------------------------------------------------
public void PrintAge( DateTime birthDate, DateTime moment )
{
Console.WriteLine( "Birthdate={0:d}, Age at {1:d} is {2} years", birthDate, moment, YearDiff( birthDate, moment ) );
} // PrintAge
Ek het ScArcher2 se oplossing gebruik vir 'n akkurate jaarberekening van 'n persoon se ouderdom, maar ek moes dit verder neem en hul maande en dae saam met die jare bereken.
public static Dictionary<string,int> CurrentAgeInYearsMonthsDays(DateTime? ndtBirthDate, DateTime? ndtReferralDate)
{
//----------------------------------------------------------------------
// Can't determine age if we don't have a dates.
//----------------------------------------------------------------------
if (ndtBirthDate == null) return null;
if (ndtReferralDate == null) return null;
DateTime dtBirthDate = Convert.ToDateTime(ndtBirthDate);
DateTime dtReferralDate = Convert.ToDateTime(ndtReferralDate);
//----------------------------------------------------------------------
// Create our Variables
//----------------------------------------------------------------------
Dictionary<string, int> dYMD = new Dictionary<string,int>();
int iNowDate, iBirthDate, iYears, iMonths, iDays;
string sDif = "";
//----------------------------------------------------------------------
// Store off current date/time and DOB into local variables
//----------------------------------------------------------------------
iNowDate = int.Parse(dtReferralDate.ToString("yyyyMMdd"));
iBirthDate = int.Parse(dtBirthDate.ToString("yyyyMMdd"));
//----------------------------------------------------------------------
// Calculate Years
//----------------------------------------------------------------------
sDif = (iNowDate - iBirthDate).ToString();
iYears = int.Parse(sDif.Substring(0, sDif.Length - 4));
//----------------------------------------------------------------------
// Store Years in Return Value
//----------------------------------------------------------------------
dYMD.Add("Years", iYears);
//----------------------------------------------------------------------
// Calculate Months
//----------------------------------------------------------------------
if (dtBirthDate.Month > dtReferralDate.Month)
iMonths = 12 - dtBirthDate.Month + dtReferralDate.Month - 1;
else
iMonths = dtBirthDate.Month - dtReferralDate.Month;
//----------------------------------------------------------------------
// Store Months in Return Value
//----------------------------------------------------------------------
dYMD.Add("Months", iMonths);
//----------------------------------------------------------------------
// Calculate Remaining Days
//----------------------------------------------------------------------
if (dtBirthDate.Day > dtReferralDate.Day)
//Logic: Figure out the days in month previous to the current month, or the admitted month.
// Subtract the birthday from the total days which will give us how many days the person has lived since their birthdate day the previous month.
// then take the referral date and simply add the number of days the person has lived this month.
//If referral date is january, we need to go back to the following year's December to get the days in that month.
if (dtReferralDate.Month == 1)
iDays = DateTime.DaysInMonth(dtReferralDate.Year - 1, 12) - dtBirthDate.Day + dtReferralDate.Day;
else
iDays = DateTime.DaysInMonth(dtReferralDate.Year, dtReferralDate.Month - 1) - dtBirthDate.Day + dtReferralDate.Day;
else
iDays = dtReferralDate.Day - dtBirthDate.Day;
//----------------------------------------------------------------------
// Store Days in Return Value
//----------------------------------------------------------------------
dYMD.Add("Days", iDays);
return dYMD;
}
SQL weergawe:
declare @dd smalldatetime = '1980-04-01'
declare @age int = YEAR(GETDATE())-YEAR(@dd)
if (@dd> DATEADD(YYYY, -@age, GETDATE())) set @age = @age -1
print @age
Hierdie klassieke vraag verdien 'n Noda Tyd oplossing.
static int GetAge(LocalDate dateOfBirth)
{
Instant now = SystemClock.Instance.Now;
// The target time zone is important.
// It should align with the *current physical location* of the person
// you are talking about. When the whereabouts of that person are unknown,
// then you use the time zone of the person who is *asking* for the age.
// The time zone of birth is irrelevant!
DateTimeZone zone = DateTimeZoneProviders.Tzdb["America/New_York"];
LocalDate today = now.InZone(zone).Date;
Period period = Period.Between(dateOfBirth, today, PeriodUnits.Years);
return (int) period.Years;
}
Gebruik:
LocalDate dateOfBirth = new LocalDate(1976, 8, 27);
int age = GetAge(dateOfBirth);
Jy sal dalk ook belangstel in die volgende verbeterings:
Deur die horlosie as 'n
IClock, in plaas daarvan om te gebruikSystemClock.Instance, sal toetsbaarheid verbeter.Die teiken tydsone sal waarskynlik verander, so jy wil 'n
DateTimeZoneparameter ook.
Sien ook my blogpos oor hierdie onderwerp: Hantering van verjaarsdae en ander herdenkings
