VBScript in a Nutshell

Name

Const Statement

Syntax

[Public|Private] Const constantname = constantvalue

constantname

Use: Required

The name of the constant.

constantvalue

Use: Required

Data subtype: Numeric or String

A constant value, and optionally, arithmetic operators. Unlike variables, constants must be initialized.

Description

Declares a constant value: i.e., its value can’t be changed throughout the life of the program or routine. One of the ideas of declaring constants is to make code easier to both write and read; it allows you to replace a value with a recognizable word.

Rules at a Glance

• The rules for constantname are the same as those of any variable: the name can be up to 255 characters in length and can contain any alphanumeric character, although it must start with an alphabetic character. In addition, the name can include almost any other character except a period or any of the datatype definition characters $ & % !.

• constantvalue can be a string or numeric literal. It can be only a single value (a simple constant); that is, it cannot be an expression that includes a call to an intrinsic or user-defined function, property, or method, nor can it contain any arithmetic or string operators or variables. In addition, a constant can’t be defined in terms of another constant, as in the statement:

  Public Const CDATE = CSTART_DATE    ' Invalid

• The Private keyword restricts the use of the constant to the module in which it’s defined, whereas the Public keyword allows the constant to be used in all procedures ...