Dec

The opposite of Inc, the function Dec decrements an integer value by 1, and provides faster and cleaner processing than using a statement like Eyes := Eyes - 1.

Unless of course you were wanting to decrease the variable Eyes by a greater number such as 10, when you would use Eyes := Eyes - 10.

Declaration: Procedure Dec(var X: Integer); overload

Examples as below.

procedure OnMapEvent(var Value:Variant);
var 
  Eyes : integer;
begin             // loop while Eyes > 10              
   Eyes := 20;
   while Eyes > 10 do
   begin
      LogInfo('Eyes is equal to '+IntToStr(Eyes));
      Dec(Eyes);
   end;
end;

This example writes a decreasing sequence of entries to the log, starting with Eyes is equal to 20, and ending with Eyes is equal to 11.