Enum type

│ English (en) │

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Range

• with 0 .. 255 characters, the data type is automatically Byte
• with 255 .. 65,535 characters, the data type is automatically Word
• over 65,535 characters, the data type is automatically Longword

Memory requirement

This depends on the data type and the number of elements. By default, an enumeration is stored in a Longword and requires 4 bytes. Depending on if a switch is used, {$PACKENUM x} (abbreviated {$Zx}) and the value range of the data type, it can be adjusted.

Memory requirements

Maximum value range	<= 255	<= 65,535	> 65,535
No switch or {$PACKENUM DEFAULT} or {$PACKENUM 4} or {$Z4}	4	4	4
{$PACKENUM 2} or {$Z2}	2	2	4
{$PACKENUM 1} or {$Z1}	1	2	4

Properties

The data type Enum Type is an enumeration of unsigned constants.

In addition, the unsigned integer data type to be used can be specified for the data type using a switch.

• at 0 .. 255 characters the switch for the byte data type:
  • {$Z1} or {$ PACKENUM 1}

• at 255 .. 65535 characters the switch for the Word data type:
  • {$Z2} or {$ PACKENUM 2}

• at 65535 .. 4294967295 characters the switch for the LongWord data type:
  • {$Z4} or {$ PACKENUM 4}

The values ​​of the enumeration always increase by 1 to the next element.

Examples

Examples of declaring the Enum data type

The values ​​of the enumeration start at 0 by default:

  Type
   {$PACKENUM 2}
   LargeEnum = (zero, one, two);

By default, the values ​​of the enumeration start at 0, unless the enumeration is assigned a different starting value. Then the count starts with the assigned initial value.

  Type
   {$PACKENUM 4}
   SmallEnum = (Six := 6, Seven, Eight);

If a higher value is assigned to an element in the middle of the enumeration, counting continues from this value.

  Type
   {$ PACKENUM 1}
   MiddleEnum = (zero, ten := 10, eleven, twelve);

Explicit use of the byte data type for the enumeration.

  Type
   byte = (zero, one, two);

Examples of assigning the Enum data type

 var 
   S : SmallEnum;
   M : MiddleEnum;
   L : LargeEnum;

Examples for the conversion of the data type Enum

  Application.MessageBox(PChar(IntToStr(Qword(Ord(Six)))), 'Conversion' , MB_OK);
  Application.MessageBox(PChar(IntToStr(Qword(Ord(p.Six)))), 'Conversion' , MB_OK);