ObjectPascal Packed Keyword Compacts complex data types into minimal storage

type Name = Packed array[...] of ...;   type Name = Packed class  ... end;   type Name = Packed object ... end;   type Name = Packed record ... end;

Description The Packed keyword tells Delphi to minimise the storage taken up by the defined object.   Normally, complex data types, such as records have their elements aligned to 2, 4 or 8 byte boundaries, as appropriate to the data type. For example, a Word field would be aligned to a 4 byte boundary.   Records are also padded to ensure that they end on a 4 byte boundary.   These alignments ensure optimal access performance.   The Packed overrides this, compressing the data into the smallest storage, albeit with consequential reduced access performance. Notes Examples of unpacked alignments : Word     = 2 bytes LongWord = 4 bytes Single   = 4 bytes Double   = 8 bytes Related commands $Align Determines whether data is aligned or packed Array A data type holding indexable collections of data Class Starts the declaration of a type of object class Object Allows a subroutine data type to refer to an object method Record A structured data type - holding fields of data		Example code : Packing a record to reduce storage type   // Declare an unpacked record   TDefaultRecord = Record     name1   : string[4];     floater : single;     name2   : char;     int     : Integer;   end;   // Declare a packed record   TPackedRecord = Packed Record     name1   : string[4];     floater : single;     name2   : char;     int     : Integer;   end; var   defaultRec : TDefaultRecord;   packedRec  : TPackedRecord; begin   WriteLn('Default record size = '+IntToStr(SizeOf(defaultRec)));   WriteLn('Packed record size = '+IntToStr(SizeOf(packedRec))); end; Show full unit code    Default record size = 20    Packed record size = 14