It leads to code that is prone to errors and more difficult to debug. You can force VBScript to require all variables to be explicitly declared by including the statement Option Explicit at the start of every script. Any variable that is not explicitly declared will then generate an error. They must be unique within the same scope. They must be no longer than 255 characters Variants and Subtypes VBScript has a single data type called a variant .
Variants have the ability to store different types of data.
The types of data that a variant can store are referred to as subtypes . The table below describes the subtypes supported by VBScript. The scope of a variable dictates where it can be used in your script. A variable's scope is determined by where it is declared. If it is declared within a procedure, it is referred to as a procedure-level variable and can only be used within that procedure.