Excel Vba Subroutine How To Call Sub In Vba With Example

In this VBA tutorial, you will learn-

Why use Subroutines
Rules of naming Subroutines and Functions
VBA Subroutine Syntax How to Call Sub in VBA

Why use Subroutines

Break code into small manageable code: An average computer program has thousands and thousands of source code lines. This introduces complexity. Subroutines help solve this problem by breaking down the program into small manageable chunks of code. Code reusability. Let’s say you have a program that needs to access the database, almost all of the windows in the program will need to interact with the database. Instead of writing separate code for these windows, you can create a function that handles all database interactions. You can then call it from whichever window you want. Subroutines and functions are self-documenting. Let’s say you have a function calculateLoanInterest and another that says connectToDatabase. By just looking at the name of the subroutine/function, the programmer will be able to tell what the program does.

Rules of naming Subroutines and Functions

To use subroutines and functions, there are set of rules that one has to follow.

A subroutine or VBA call function name cannot contain space An Excel VBA Call Sub or function name should start with a letter or an underscore. It cannot start with a number or a special character A subroutine or function name cannot be a keyword. A keyword is a word that has special meaning in VBA. Words like Private, Sub, Function, and End, etc. are all examples of keywords. The compiler uses them for specific tasks.

VBA Subroutine Syntax

You will need to enable the Developer tab in Excel to follow along with this example. If you do not know how to enable the Developer tab then read the tutorial on VBA Operators HERE in the syntax,

Private Sub mySubRoutine(ByVal arg1 As String, ByVal arg2 As String) ‘do something End Sub

Syntax explanation The following subroutine accepts the first and last name and displays them in a message box. Now we are going to program and execute this Sub Procedure. Let see this.

Summary:

A subroutine is a piece of code that performs a specific task. A subroutine does not return a value after execution Subroutines offer code reusability Subroutines help break down large chunks of code into small manageable code.

Design the user interface and set the properties for the user controls. Add the subroutine Write the click event code for the command button that calls the subroutine Test the application

Step 1) User Interface Design the user interface as shown in the image below.

Set the following properties. The properties that we are setting:

Step 2) Add subroutine

Press Alt + F11 to open the code window Add the following subroutine

Private Sub displayFullName(ByVal firstName As String, ByVal lastName As String) MsgBox firstName & " " & lastName End Sub

HERE in the code, Step 3) Calling the subroutine Calling the subroutine from the command button click event.

Right click on the command button as shown in the image below. Select View Code. The code editor will open

Add the following code in code editor for the click event of btnDisplayFullName command button.

Private Sub btnDisplayFullName_Click() displayFullName “John”, “Doe” End Sub

Your code window should now look as follows

Save the changes and close the code window. Step 4) Testing the code On the developer toolbar put the design mode ‘off’. As shown below.

Step 5) Click on the command button ‘FullName Subroutine’. You will get the following results

Download the above Excel Code