Find the last Sunday of each month: Difference between revisions

=={{header|Delphi}}==

{{libheader| System.SysUtils}}

{{libheader| System.DateUtils}}

{{Trans|C#}}

<lang Delphi>

program Find_the_last_Sunday_of_each_month;

{$APPTYPE CONSOLE}

uses

System.SysUtils,

System.DateUtils;

// ADayOfWeek -> sunday is the first day and is 1

function LastDayOfWeekOfEachMonth(AYear, ADayOfWeek: Word): TArray<TDateTime>;

var

month: word;

daysOffset: Integer;

date: TDatetime;

begin

if (ADayOfWeek > 7) or (ADayOfWeek < 1) then

raise Exception.CreateFmt('Error on FindAllDaysOfWeek: "%d" must be in [1..7] (sun..sat)',

[ADayOfWeek]);

SetLength(Result, 12);

for month := 1 to 12 do

begin

date := EncodeDate(AYear, month, DaysInAMonth(AYear, month));

daysOffset := DayOfWeek(date) - ADayOfWeek;

if daysOffset < 0 then

inc(daysOffset, 7);

Result[month - 1] := date - daysOffset;

end;

end;

var

strYear: string;

Year: Integer;

date: TDateTime;

begin

write('Year to calculate: ');

Readln(strYear);

if not TryStrToInt(strYear, Year) or (Year < 1900) then

raise Exception.CreateFmt('Error: "%s" is not a valid year', [strYear]);

for date in LastDayOfWeekOfEachMonth(Year, 1) do

writeln(FormatDateTime('yyyy-mmm-dd', date));

readln;

end.</lang>