ByRef and ByVal in vbscript

Here is an interesting post by Eric Lippert explaining how to pass variables to vbscript subroutines and functions without using ByRef or ByVal:

Sub Bar(x)
End Sub

Sub Baz(a, b)
End Sub

Function Foo(y)
End Function

z = 123
n = Foo(z)         ' legal, passes z by reference
n = Foo((z))       ' legal, passes z by reference
'n = Foo z         ' illegal, parens required
Foo z              ' legal, passes z by reference
Foo(z)             ' legal, passes z by value
'Call Foo z        ' illegal, parens required
Call Foo(z)        ' legal, passes z by reference
Call Foo((z))      ' legal, passes z by value
'n = Bar(z)        ' illegal, bar is not a function
Bar z              ' legal, passes z by reference
Bar(z)             ' legal, passes z by value
Call Bar(z)        ' legal, passes z by reference
Call Bar((z))      ' legal, passes z by value
Baz z, z           ' legal, passes z by reference
Baz (z), (z)       ' legal, passes z by reference
'Baz(z,z)          ' illegal, can't use parens
Call Baz(z, z)     ' legal, passes z by reference
Call Baz((z), (z)) ' legal, passes z by value
'Call Baz z, z     ' illegal, parens required

So basically if you want to pass a variable by value you need to wrap it in an extra set of brackets