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**VIRTUAL**

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The **VIRTUAL** attribute specifies that the PROCEDURE on whose prototype it is placed is a virtual method of the CLASS containing the prototype. This allows methods in a parent CLASS to access methods in a derived CLASS. The VIRTUAL attribute must be placed on both the method's parent class prototype and the derived class's prototype.

**Example:**

**OneClass  CLASS                         !Base class**

**BaseProc   PROCEDURE(REAL Parm)         !Non-virtual method**

**Proc       PROCEDURE(REAL Parm),****VIRTUAL**** !Declare a virtual method**

**          END**

**TwoClass  CLASS(OneClass)               !Derived class of OneClass**

**Proc       PROCEDURE(REAL Parm),****VIRTUAL**** !Declare a virtual method**

**          END**

**ClassThree OneClass         !Another Instance of a OneClass object**

**ClassFour  TwoClass         !Another Instance of a TwoClass object**

** CODE**

** OneClass.BaseProc(1)       !BaseProc calls OneClass.Proc**

** TwoClass.BaseProc(2)       !BaseProc calls TwoClass.Proc**

** ClassThree.BaseProc(3)     !BaseProc calls OneClass.Proc**

** ClassFour.BaseProc(4)      !BaseProc calls TwoClass.Proc**

**OneClass.BaseProc  PROCEDURE(REAL Parm)**

** CODE**

** SELF.Proc(Parm)            !Calls virtual method, either OneClass.Proc **

**                            ! TwoClass.Proc, depending on which**

**                            ! class instance is executing**

**See Also:**

[[class  object declaration .htm|CLASS]]

[[derived  prevent function overloading .htm|DERIVED]]