Delphi in a Nutshell

Name

Inc Procedure

Syntax

procedure Inc(var Variable);
procedure Inc(var Variable; Count: Integer);

Description

The Inc procedure increments a variable. You can increment any ordinal-type variable or pointer-type variable. You cannot use Inc to increment a floating-point variable.

Incrementing a pointer adjusts the pointer by the size of the base type. For example, incrementing a pointer to AnsiChar increases the pointer value by 1, and incrementing a pointer to WideChar increases the pointer value by 2. The default is to increment the variable by 1 unit, but you can supply an integer to increment by a different amount. When incrementing a pointer, Count is multiplied by the size of the base type.

The Inc procedure is built-in and is not a real procedure.

Tips and Tricks

• Count can be negative, in which case the variable’s value decreases.

• There is little performance difference between Inc, Succ, or addition. That is, the following all result in similar object code:

Inc(X);
X := Succ(X);
X := X + 1;    // if X is an integer or PChar type

• You cannot use a property for the variable because a property value cannot be used as a var parameter. Use a simple assignment instead.

See Also

Dec Procedure, High Function, Low Function, Pred Function, Succ Function