Browse DevX
Sign up for e-mail newsletters from DevX

Tip of the Day
Language: Visual Basic
Expertise: Advanced
Jul 30, 1997



Building the Right Environment to Support AI, Machine Learning and Deep Learning

Implementation of Public Forms and Class Variables

The implementation of Public variables in forms and classes changed with Visual Basic 5.0. VB4 implements public variables in forms and class modules as if they're regular variables, using pointers to data in memory. In VB5, public variables are more correctly implemented as a pair of hidden Get/Let property procedures. This approach slows down these properties when the program is ported from VB4 to VB5. More importantly, this change likely breaks any code that relies on passing such variables to procedures as ByRef arguments and expects that the procedure modifies them. In fact, under VB5, they're passed by value, and the original property is never affected. For more information on this issue, see article Q166928 in the Microsoft Knowledge Base.
Francesco Balena
Comment and Contribute






(Maximum characters: 1200). You have 1200 characters left.



Thanks for your registration, follow us on our social networks to keep up-to-date