Vba excel define constant

This tutorial will demonstrate the use of VBA Constants.

A constant is similar to a variable and is declared in a similar way.  There is, however, a major difference between them!

What is a Constant

A constant is a value that we declare in our code and consequently it is reserved in our computer’s memory and stored. We have to name our constant and it’s good practice to declare the data type of our constant. When we declare the data type, we are telling the program what type of data needs to be stored by our constant .

We will use the constant in our code, and the program will also access our constant. Unlike a variable, where the actual value can change while the code is running, a constant value never changes.

Data Types used by Constants

Constants use the same data type as Variables.   The most common data types for Constants are as follows:

• String – this is used to store text values.
• Boolean – this is used to store TRUE or FALSE values.
• Integer – this is used to store whole number values.
• Double – this is used to store numbers with decimals.
• Date – this is used to store dates.

To see a complete list of all data types used by Variables and Constants in VBA, click here.

In VBA, we have to use a Const statement in order to declare a Constant.  We can declare constants in a similar way to declaring Variables – at Procedure Level, at Module Level and at a Global Level.

Declaring a Constant within a Procedure

To declare a Constant at Procedure level, we declare it inside the procedure.

Sub CompanyDetails()
   Const strCompany As String = "ABC Suppliers"
   Const strAddress As String = "213 Oak Lane, Highgate"
   MsgBox strCompany & vbCrLf & strAddress
End Sub

When we run the code, the message box will return the constant values.

Because the Constant is declared at Procedure level, we  can declare a Constant with the same name in a different Procedure.

If we run the second Procedure, the Constant value stored in that Procedure is returned.

Declaring a Constant within a Module

If we want a Constant value to be available to all Procedures within a Module, we need to declare the constant at Module level.

This will make the same constant available to multiple procedures WITHIN that module only.

Should you use the Constant in a different module, an error will occur.

Declaring Constants at a Global Level

You can declare Constants at a Global Level which would then mean you can use them in all the Modules contained in your entire VBA Project.

To declare a Constant as a Global Constant, we need to put the word PUBLIC in front of the declaration statement.

For example:

Public Const strCompany as string = "ABC Suppliers"

This will allow the Constant to be used in all the modules regardless of where is is declared.

NOTE: you can ONLY declare a public constant at a Module level, you CANNOT declare a public constant within a procedure.

What is VBA Const (Constants)?

Variables are the heart and soul of any programming language. We have never seen a coder or developer who does not rely on variables in their project or program. As a coder, no one is not different from others. We use variables 99% of the time. We all use the “Dim” statement; we declare VBA variablesVariable declaration is necessary in VBA to define a variable for a specific data type so that it can hold values; any variable that is not defined in VBA cannot hold values.read more. Our articles have shown you about declaring variables through the “Dim” statement. But we declare variables using another way as well. This article will show you the alternative route of declaring variables, i.e., the “VBA Constant” method.

“Const” stands for “Constants” in VBA. Using the VBA “Const” word, we can declare variables like how we declare variables using the “Dim” keyword. We can display this variable at the top of the module, between the module, in any subroutine in VBASUB in VBA is a procedure which contains all the code which automatically gives the statement of end sub and the middle portion is used for coding. Sub statement can be both public and private and the name of the subprocedure is mandatory in VBA.read more and function procedure, and the class module.

To declare the variable, we need to use the word “Const” to display the constant value. Once the variable is declared and assigned a cost, we cannot change the weight throughout the script.

You are free to use this image on your website, templates, etc, Please provide us with an attribution linkArticle Link to be Hyperlinked
For eg:
Source: VBA Const (wallstreetmojo.com)

Syntax of Const Statement in VBA

The Const statement is slightly different from the “Dim” statement. To understand it better, let us look at the well-written syntax of the VBA Const statement.

Const [Variable Name] As [Data Type] = [Variable Value]

• Const: With this word, we initialize the process of declaring the constants.
• Variable Name: This is as usual as naming the variable. We rather call it Const Name instead of Variable Name.
• Data Type: What kind of value our declared variable is going to hold.
• Variable Name: Next and final part is what is the value we are going to assign to the variable we have declared. The given weight should be as per the data type.

Condition of Constants in VBA

• The name of the constant we are declaring can contain a maximum of 256 characters in length.
• The constant’s name cannot start with a number; rather, it should begin with the alphabet.
• We cannot VBA reserved keywords to declare the constants.
• The constant name should not contain any space or special characters except the underscore character.
• One can declare multiple constants with a single statement.

Examples of Const Statement in VBA

Let’s declare your first variable through the VBA Const statement. After that, we can declare constants at the subprocedure, module, and project levels.

Now, look at how to declare at the sub procedure level.

In the above example, we declared constant “k” inside the sub procedure named Const_Example1(). And we have assigned the value as 75.

Now, look at the module level Constant declaration.

At the top of the module, we have declared three constants in the module “Module 1”.

These VBA constants can be accessed in “Module 1” at any sub procedures within this module, i.e., “Module 1.”

Make Constants Available Across Modules

We can access those constants within the module with all the subprocedures when we declare the constants at the top of the VBA class moduleUsers have the ability to construct their own VBA Objects in VBA Class Modules. The objects created in this module can be used in any VBA project.read more.

But how can we make them available with all the modules in the workbook?

To make them available across modules, we need to declare them with the word “Public.”

Now, the above variable is not only available with “Module 1.” Instead, we can use “Module 2” as well.

Difference Between VBA Dim Statement & Const Statement

It would help if you doubted the difference between the traditional “Dim” statement and the new “Const” statement in VBA.

We have one difference with these, i.e., look at the below image.

In the first image, as soon as we declare a variable, we have assigned some values to them.

But in the second image, using the “Dim” statement first, we have declared variables.

After declaring a variable, we have assigned values separately in the different lines.

Like this, we can use the VBA “Const” statement to declare constants, which is a similar way of communicating variables with the “Dim” statement.

Recommended Articles

This article has been a guide to VBA Const (Constants). Here we discuss how to use the Constant statement in VBA along with examples and its critical differences with Dim information. Below are some useful Excel articles related to VBA: –

• VBA Do Loop
• VBA DoEvents
• VBA Option Explicit
• VBA Text