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**REPLACE**

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The **REPLACE** attribute specifies that the PROCEDURE on whose prototype it is placed completely replaces the constructor or destructor from its parent class. REPLACE is valid only on a PROCEDURE labelled either "Construct" or "Destruct" and declared within a CLASS structure which is derived from a class which also contains a matching "Construct" or "Destruct" PROCEDURE. If the PROCEDURE label is "Construct" the method is a Constructor--automatically called when the object is instantiated. An object is instantiated when it comes into scope or when created with a NEW statement. If the PROCEDURE label is "Destruct" the method is a Destructor--automatically called when the object is destroyed. An object is destroyed when it goes out of scope or when destroyed with a DISPOSE statement.

**Example:**

**  PROGRAM**

**SomeQueue QUEUE,TYPE**

**F1         STRING(10)**

**          END**

**OneClass  CLASS,MODULE('OneClass.CLW'),TYPE **

**ObjectQueue &SomeQueue             !Declare a reference to a named queue**

**Construct   PROCEDURE              !Declare a Constructor**

**Destruct    PROCEDURE              !Declare a Destructor**

**          END**

**TwoClass  CLASS(OneClass),MODULE('TwoClass.CLW'),TYPE **

**Construct   PROCEDURE,****REPLACE****      !Declare a replacement Constructor**

**          END**

**MyClass   OneClass                 !Instance of OneClass**

**YourClass  &TwoClass               !Reference to TwoClass**

** CODE                              !MyClass object comes into scope, **

**                                   !autocalling OneClass.Construct **

** YourClass &= NEW(TwoClass)        !YourClass object comes into scope,**

**                                   !autocalling TwoClass.Construct **

** DISPOSE(YourClass)                !YourClass object goes out of scope,**

**                                   !autocalling OneClass.Destruct **

** RETURN                            !MyClass object goes out of scope,**

**                                   !autocalling OneClass.Destruct **

**!OneClass.CLW contains:**

**OneClass.Construct  PROCEDURE**

** CODE**

** SELF.ObjectQueue = NEW(SomeQueue) !Create the object's queue**

**OneClass.Destruct  PROCEDURE**

** CODE**

** FREE(SELF.ObjectQueue)            !Free the queue entries**

** DISPOSE(SELF.ObjectQueue)         ! and remove the queue**

**!TwoClass.CLW contains:**

**TwoClass.Construct  PROCEDURE**

** CODE**

** SELF.ObjectQueue = NEW(SomeQueue) !Create the object's queue**

** SELF.ObjectQueue.F1 = 'First Entry'**

** ADD(SELF.ObjectQueue) **

**See Also:**

[[new  allocate heap memory .htm|NEW]]

[[dispose  de allocate heap memory .htm|DISPOSE]]

[[class  object declaration .htm|CLASS]]