Declare variables in Classes

Hi Everyone,

Just wanting to ask why it seems not possible to declare variables in Class modules like so:

Option Explicit

Private Variable_A as VarType_A '<<<<< is this not possible and why?

Function_A_In_Class_Module(var as vartype) as 
    '-----work
    '-----work
    '-----work
    '-----work
End Function

Thanks in advance.