Dec

Decrease value of variable

Declaration

Source position: line 0

Description

Dec decreases the value of X with Decrement. If Decrement isn't specified, then 1 is taken as a default.

Errors

A range check can occur, or an underflow error, if an attempt it made to decrease X below its minimum value.

See also

Example

Program Example14;

{ Program to demonstrate the Dec function. }

Var
  I  : Integer;
  L  : Longint;
  W  : Word;
  B  : Byte;
  Si : ShortInt;

begin
 I:=1;
 L:=2;
 W:=3;
 B:=4;
 Si:=5;
 Dec (i);    { i:=0  }
 Dec (L,2);  { L:=0  }
 Dec (W,2);  { W:=1  }
 Dec (B,-2); { B:=6  }
 Dec (Si,0); { Si:=5 }
end.

Dec / Inc and PChar

It appears that FreePascal (as at least of version 2.04) allows to apply Dec / Inc on elements of type PChar (to be used carefully, as it is not a recommanded practice).

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+ Summary manual of Gnat, an Ada compiler
+ ANSI_Console, an Ada package for console applications using ANSI/ECMA terminal commands

-- Yannick Duchêne on May 15, 2007 03:15 AM (view details)