How to Call a Function in VB

Last Updated: November 16, 2021 Tested

Stuck with concepts of "Function" in VB ? If Yes, read this guide to learn the so called constructs of "Function" in the paradigm of VB.

Steps

1
What is Function ?
- Use a Function procedure when you need to return a value to the calling code.
- A function itself has a type, and the function will return a value to the calling subroutine based on the code that it contains.
2
How to declare Function ?
- You can define a Function procedure only at module level. This means the declaration context for a function must be a class, structure, module, or interface, and cannot be a source file, namespace, procedure, or block.
- A function is declared the exact same way as a subroutine, except using the "Function" keyword instead of "Sub".
- Function procedures default to public access. You can adjust their access levels with the access modifiers.
3
How to call Function ?
- You call a Function procedure by using the procedure name, followed by the argument list in parentheses, in an expression.
- You can omit the parentheses only if you are not supplying any arguments. However, your code is more readable if you always include the parentheses.
- A function can also be called using the Call statement, in which case the return value is ignored.
- To return a value, assign a value of the proper type to the function's name, as if it were a variable.

Community Q&A

Question

How do I run a function in VB.net?

Snod

Community Answer

Click Compile then Run using the menu. There may also be keyboard shortcut hotkeys.

Syntax

Declaration

[ <attributelist> ] [ accessmodifier ] [ proceduremodifiers ] [ Shared ]
Function name [ (Of typeparamlist) ] [ (parameterlist) ] [ As returntype ]
    [ statements ]
    [ Exit Function ]
    [ statements ]
End Function

Calling

'Without Call
Function_Name()
    
'With Call
Call Function_Name()

Example

An example of function that adds two numbers is shown below

Private Function Add(ByVal x As Integer, ByVal y As Integer) As Integer
    Dim Res as integer
    Res = x + y
    Add = Res
End Function
 
Private Sub Form_Load()
    Dim a As Integer
    Dim b As Integer
    Dim c As Integer
    a = 32
    b = 64
    c = Add(a, b)
    MsgBox ("Sum is : " & c)
End Sub