Parameter changing once function run

[Lavina]

Hey guys, i am making a small function to add up all the numbers between 2 numbers.

My code:

Sub Sums()    Dim a As Long, b As Long, i As Long, n As Long, ta As Long, tb As Long, ak As Long, bk As Long
    a = 0
    b = -2
    ak = 1
    bk = 1
    If a - b = 0 Or a + b = 0 Then
        n = 0
    Else:
        If a = b Then
            n = a
        Else:
            If a < 0 Then ak = -1
            If b < 0 Then bk = -1
            ta = Tria(a, ak)
            tb = Tria(b, bk)
        End If
    End If
    If a > b Then
        n = ta - tb
    Else:
        n = tb - ta
    End If
    Debug.Print n
End Sub


Function Tria(n As Long, k)
    n = (n * (n + k)) / 2
    Tria = n
End Function

Whenever i call the function: tb = Tria(b, bk), my variable b gets changed in the process. Why is this happening?

Of course if i just do: Tria = (n * (n + k)) / 2 it all works, but i was under the impression that if my variable was dimmed in a separate sub and it should not be reachable? Or do functions work different?

 

[joeu2004]

Change the function declaration to Function Tria(ByVal n As Long, k). By default, VBA passes parameters "by reference" (ByRef).

 

[mohadin]

Hi
try

Function Tria(nn As Long, kk)
    nn = (nn * (nn + kk)) / 2
    Tria = nn
End Function

 

[Lavina]

Change the function declaration to Function Tria(ByVal n As Long, k). By default, VBA passes parameters "by reference" (ByRef).

Ah, i see now, thank you!