VBScript - ByVal Vs ByRef / VBScript Passing Values ByRef or ByVal

Let Us See how we can get values by Reference and by Values :

In VBScript ByRef and ByVal:

<%

Function MyFunctionByRef(ByRef Myvalue)

      Myvalue = Myvalue + 1

End Function

Dim sendvalues : sendvalues = 3

Dim MyOutput: MyOutput = MyFunctionByRef(sendvalues)

Response.write "MyOutput: " & MyOutput  '4

%>

<%

Function MyFunctionByVal(ByVal Myvalue)

     Myvalue = Myvalue + 1

End Function

Dim sendvalues : sendvalues = 3

Dim MyOutput: MyOutput = MyFunctionByVal(sendvalues)

Response.write "MyOutput: " & MyOutput '4

%>

Passing Parameters ByRef and ByVal

In VBScript, there are two ways values can be passed:
1) ByVal

2) ByRef

Using ByVal, we can pass arguments as values whereas with the use of ByRef, we can pass arguments are references.
ByVal:

the parameter is passed by value, thus the subroutine works with a copy of the original.
ByRef:

the parameter is passed by reference, thus the subroutine works directly with the original.


Example: Parameters By Value


Function GetValue( ByVal var )
var = var + 1
End Function

Dim x: x = 5

'Pass variable x to GetValue function ByVal
GetValue x

Response.write "x = " & x

Output: x = 5

Example: Parameters By Reference:


Function GetReference( ByRef var )
var = var + 1
End Function

Dim x: x = 5

'Pass the variable x to the GetReference function ByRef
GetReference x

Response.write x

Output: 6