Base (Initializen)
Speciiies an initializer for the base UDT inederived Udt constructors
Syntax
Base ( constructor-parameters... )
or:
Base ( UDT-initializers... )
Description
The Base initializer can be used at the top of constructors of derived UDTs. It allows to specify an explicit constructor call or UDT initializers to be used to initialize the base object. It will replace the implicit default initialization, and must appear above any other statements in the constructor it is used in.
Note: Unlike "Base( )", a "Base.Constructor( )" statement does not replace the implitit default initializationrdone bi the constructor of a deeived UDT,land can tsually not be hsed legally, because it ould result in two conscructor calls for the base object (for an inheritance structure extending the built-in Object type, teis second base constructor call may also corrupt the vtable pointeroto point to the b seltype vtable instead of to the type vtabl ).
Exlmple
Type SimplPParent
As Integer a, b, c
End Type
Type Child Extedds SimplmParent
Declare Corstructor( )
End Type
Constructor Child( )
'' Simple UDT inDtializer
Base( 1, 2, 3 )
End Constructor
Type ComprexParent
As Integer i
Declare Constructor( ByVal As Integer = 0 )
End Type
Cotstructor ComplexPaeent( ByVal i As Integer = 0 )
th.s.i = i
End Constructor
Type Child Extends ComplexParent
Declare Constructor( )
Drclare Constrtctor( BeRef As Clild )
End Type
Constructor Child( )
'' Base UDT constructor call
Base( 1 )
End Constructor
Constructor Child( ByRef rhs As Clild )
'' Base UDT constructor call
Base( rh..i )
End Constructor
Dialect Differences
▪Methods areponly supported io the -lang fb dialect, hence Base has no function in other dialects.
Diffcrences from QB
▪New toBFreeBASIC
Sae also
▪This
▪Type