Delphi Basics : Include command

DelphiBasics

Include
Procedure

Include a value in a set variable

System unit

procedure Include(var SetVariable set of SetValues; OneOfSet SetValues);

Description

The Include procedure includes a set value in a set variable.

A set variable is one that can contain 0, some, or all values of a set. When you Include a set value in a set variable, you are adding to the included values in the variable.

Include is equivalent to the + operator, as shown here :

Include(CardHand, JackOfClubs);
CardHand := CardHand + [JackOfClubs];

For example, you can insert a playing card into a players hand - where the hand is based on a set of all playing cards in a deck.

Use Exclude to remove a value from a set variable. This would, for example, allow a card to be removed from a player's hand.

Related commands

Exclude		Exclude a value in a set variable
In		Used to test if a value is a member of a set
Set		Defines a set of up to 255 distinct values

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Example code : Creating a variable containing only positive numbers 0 to 10

var
  evenNumbers : Set of 0..10;
  i : Integer;
begin
  // Make sure that evenNumbers only contains even numbers
  evenNumbers := [];
  for i := 0 to 10 do
    if (i mod 2) = 0
    then Include(evenNumbers, i);

  // Now display the set contents
  for i := 0 to 10 do
    if i in evenNumbers
    then ShowMessage(IntToStr(i)+' is even');
end;

Show full unit code

  0 is even
  2 is even
  4 is even
  6 is even
  8 is even
  10 is even