Get the latest 'N' quarters in C #

Question

Suppose the current quater is 3 and the year is 2011. How can I get the last 5 quarters

Required Conclusion:

Q3-2011 Q2-2011 Q1-2011 Q4-2010 Q3-2010 

Added Q and '-' values.

I try as under

 int generateQuater = 5; int currentQuater = 3;//GetQuarter(DateTime.Now.Month); int currentYear = DateTime.Now.Year; List<string> lstQuaterYear = new List<string>(); lstQuaterYear.Add(string.Concat('Q',currentQuater, '-', currentYear)); for (int i = generateQuater; i > 0; i++) { //code to be placed } 

thanks

Answer 1

You must reduce the loop variable. The rest is not too complicated math. It also does not need to handle the first iteration in any special way:

 for (int i = generateQuater; i > 0; i--) { lstQuaterYear.Add(string.Format("Q{0}-{1}", currentQuater, currentYear)); if (--currentQuater == 0) { currentQuater = 4; currentYear--; } } 

Answer 2

As a pure LINQ expression:

  public IEnumerable<String> GetQuarters(int start, int year, int count) { return (from q in Enumerable.Range(0, count) select String.Format("Q{0}-{1}", (start - q) + (((q + 1) / 4) * 4) , year - ((q + 1) / 4))); } 

Mathematics is somewhat ugly, but it works, you can use it:

 foreach (String quarter in GetQuarters(3, 2011, 5)) { Console.WriteLine(quarter); } 

Answer 3

Your for loop should go from 0 to your variable when you increment i.

The internal code might be something like this:

 currentQuarter--; if(currentQuarter == 0) { currentQuarter = 4; currentYear--; } 

Answer 4

Do not forget to reorganize it :)

  int count = 5; int currentQuarter = GetQuarter(DateTime.Now.Month); int currentYear = DateTime.Now.Year; List<string> lstQuaterYear = new List<string>(); for (int i = count; i > 0; i--) { lstQuaterYear.Add(string.Concat('Q', currentQuarter, '-', currentYear)); currentQuarter--; if (currentQuarter == 0) { currentQuarter = 4; currentYear--; } } 

Answer 5

One way is to check the transshipment of the year, and then set the quarter to 4 and reduce the year:

 int quarter=3; int year=2011; int count=5; for(int i=0;i<count;i++) { lstQuaterYear.Add(string.Format("Q{0} {1}", quarter, year); quarter--; if(quarter==0) { quarter=4; year--; } } 

Alternatively, you can calculate totalQuartal=year+quartal-1 . Then reduce it at each step. Finally, use year=totalQuartal/4 and quartal=totalQuartal%4+1 . But I think the first way is easier to understand.

Answer 6

 public static IEnumerable Generate(int number, int currentYear, int currentQuarter) { int counter = number; int quarter = currentQuarter; int year = currentYear; while (counter-- > 0) { yield return String.Format("Q{0}-{1}", year, quarter); quarter = quarter>1?quarter-1:4; year = quarter==4?year-1:year; } } 

Answer 7

Here is my version (sorry, this is in VB.NET).

The idea is as follows:

• it's easy to find a quarter by date (easy: divide it by 4 ... and add 1 to avoid zeros)
• return on time from the current date by deleting 3 months at every moment
• print formatted quarter

the code:

 Private Shared Function GetQuarterForDate(ByVal d As DateTime) As Integer Return (d.Month \ 4) + 1 'integer division End Function Private Shared Function GetLastNQuarters(ByVal N As Integer) As IEnumerable(Of String) Dim myDate = DateTime.Now Dim res As New List(Of String)() Do While N > 0 'using yield would be nicer in C# ... does not exist in VB res.Add(String.Format("Q{0}-{1}", GetQuarterForDate(myDate), myDate.Year)) myDate = myDate.AddMonths(-3) N = N - 1 Loop Return res End Function <TestMethod()> Public Sub CanRetrieveQuarter() Dim quarters = GetLastNQuarters(5) For Each q In quarters Console.WriteLine(q) Next End Sub 

This last “test method” prints:

 Q3-2011 Q2-2011 Q1-2011 Q4-2010 Q3-2010 

Answer 8

If you want to do some operations for a quarter, for example, check if the moment is within a quarter, you can use the Quarter “Time Library” class for .NET :

 // ---------------------------------------------------------------------- public ITimePeriodCollection GetPastQuarters( int count ) { TimePeriodCollection quarters = new TimePeriodCollection(); Quarter quarter = new Quarter(); for ( int i = 0; i < count; i++ ) { quarters.Add( quarter ); quarter = quarter.GetPreviousQuarter(); } return quarters; } // GetPastQuarters