System.Inc

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Delphi

procedure Inc(var X: Integer); overload;
procedure Inc(var X: Integer; N: Integer); overload;

Properties

Type Visibility Source Unit Parent
procedure public System.pas System System

Description

Increments an ordinal value by 1 or N.

In Delphi code, Inc adds 1 or N to the variable X.

X is a variable of an ordinal type (including Int64) or a pointer type if the extended syntax is enabled.

N is an integer-type expression.

X increments by 1 or by N if N is specified, for example:

  • Inc(X) corresponds to the statement X := X + 1
  • Inc(X, N) corresponds to the statement X := X + N.

On some platforms, Inc may generate optimized code, especially useful in tight loops.

If X is a pointer type, it increments X by N times the size of the type pointed to. Thus, given:

 type
   PMyType = ^TMyType;

and

 var
   P: PMyType;

The statement Inc(P) increments P by SizeOf(TMyType).

Warning: You cannot use Inc on properties, because it modifies the parameter.
Note: Inc(S, I), where S is a ShortInt and I is a number greater than 127 causes an EIntOverFlow exception to be raised, if range and overflow checking are on. In Delphi 1.0, this did not raise an exception.

See Also

Code Examples