variable problem

[mshahid]

i am new in vb i am trying to demonstrates a function that returns a customer data type. but i got the errors

"Warning 1 Variable 'Company' is used before it has been assigned a value. A null reference exception could result at runtime",
Warning 2 Variable 'Address' is used before it has been assigned a value. A null reference exception could result at runtime,
"Warning 3 Variable 'city' is used before it has been assigned a value. A null reference exception could result at runtime.
" Warning 4 Variable 'Country' is used before it has been assigned a value. A null reference exception could result at runtime".

i have tried to solve these but not fix these errors. please tell me how to fix these

Thanks in advance

 

[JohnH]

Generally you should declare the variable when you need it and assign it a value directly, for example instead of this:

Dim b As Button
b = New Button

you do this:

Dim b As Button = New Button

or better yet the short form:

Dim b As New Button

If this is not possible you can explicitly assign a null reference to get rid of the warning:

Dim b As Button = Nothing
If condition Then
    b = new Button
Else ...

By doing this you're telling compiler you're aware that this variable is initially a null reference, and implicitly that you should be taking precautions to avoid causing a null reference exception at runtime later in code.

 

[Solitaire]

Try assigning a blank string to each of the variables right at the beginning. Example:
Dim company As String = ""