Record’s variant

A record can have one or more variant elements or fields. This variant allows data to accessed using one or more different fields. To declare a record contain variant use these statements :

Type

   RecordTypeName = record

      Field_1 : type_1;

      ..

      ..

      Field_n : type_n;

      Case Tag : OrdinalType of

         Constant_1 : ( variant_1);

         Constant_2 : ( variant_2);

      End;

Example record contain variant :

Type

   TCategory = (FullTimer, PartTimer);

   TEmployeeRecord : record

     Name : String(30);

     Case Category : TCategory of

       Full Time : ( Salary : currency;

                              Bonus : currency);

       Part Time : (  Salary : currency);

     End;

Example program :

program Project1;
{$APPTYPE CONSOLE}
uses
   SysUtils;

type
   TCategory = ( FullTimer, PartTimer );
   TEmployeeRecord = record
       Name : String[30];
       Case Category : TCategory of
          FullTimer : ( Salary : currency;
                                  Bonus : currency);
          PartTimer : ( Payment : currency);
   end;

var
   Employee : TEmployeeRecord;

begin
  with Employee do
    begin
     // assigning fields' values
     Name := 'Albert Einstein';
     Category := FullTimer;
     Salary := 1000;
     Bonus := 100;
     // writing fields' values
     writeln('Name : ',Name);
     writeln('Salary : ',Salary:10:2);
     writeln('Bonus : ',Bonus:10:2);
     // assigning fields' values
     Name := 'Albert Einstein';
     Category := PartTimer;
     Payment := 500;
     // writing fields' values
     writeln('Name : ',Name);
     writeln('Payment : ',Payment:10:2);
    end;
  readln;
end.

You can download the complete code here.