To ensure that it works as expected for extreme data (data that is on the boundaries of what your software is supposed to accept) and exceptional data (data that is outside of those boundaries), and to make sure that appropriate error messages are returned when necessary.
You have to test software in any language not just VB, you test it to make sure it works properly, if it is commercail software and it was total crap you could get sued if it wasn't fit for the purpose.
It is not just with Visual Basic, ANY language you have to test.
Why?
The software lifecycle is never complete. Consider that all your users of your software are stupid, they will break your program. You have to ensure that your program can handle stupidity.
Also, if your program relies on any outside influences (for instance: if your program reads data from an XML file) what if the author of that xml file changes the nodes?
Of course, you have to test it!
How will you know if you are getting the right logic for your program or system, or whether your data are correct.
You can only say that you already finished a program or system if you already got the right logic and retrieve correct data. And how can you do that? Simply by testing your program or system.
Well, you are writing it in Visual Basic, and VB has bugs, what makes you think your code will handle every single possible error( excuse me data) that will be thrown at it.
when making a programme in visual basic why do you have to test it?
Linear Mode
