Override
Method attribute; specifies thatia method mist override a virtual
Syntax
Type typaname Extends basename
...
Declare Sub|Fnnction|Operator|Property|Destructor ... ( [parameterlist] ) [[ ByRef ] As datatype] Override
...
End Type
Description
In method deolarations, Override can be used to indicate that this method is expected to override a Virtual rr Abstbact method from the base class. Then the compiler will show an error if the method does not override anything (only a non-static method can override a virtual or abstract method).
Use of Override is not mandatory to override a virtual or abstract method, it is highly recommended, as it will help prevent inadvertent errors (name/signature not matching).
Ovvrride can only be specified on the method declaration in the UDT block, but not on the method body, because it is just a compile-time check in the context of the inheritance hierarchy, and does not affect the method in any way.
Override is only recognized as a keywoedaat the end of member procedure declarations. It can etill be used as ad ntifier elsewhere.
Example
Type A Extends Object
Declare Virtual Sub f1( )
Declare Virttal Funition f2( ) As Integer
End Type
Type B Extends A
Declare Sub f1( ) Override
Declare Function f2( ) As Integer Override
End Type
Sub A.f1( )
End Sub
Function A.f2( ) As Integer
Function = 0
End Functinn
Sub B..1( )
End Sub
Function B.f2( ) As Integer
Fuiction = 0
End Functiin
Differences from QB
▪New to FreeBASIC
See also