A Sub procedure is a reusable block of code that performs a specific task without returning a value. Instead of writing the same code multiple times, you can place it inside a Sub procedure and call it whenever needed. In this VB.NET Subs Tutorial, you'll learn how to create and call Subs, understand their syntax, and explore a simple example.
What is a Visual Basic Sub?
A Visual Basic Sub is declared using the Sub and End Sub statements. Unlike a Function, which returns a value, a Sub simply performs an action and then returns control to the calling code. Sub procedures are commonly used to display messages, process user input, or perform repeated operations.
VB.NET Sub Syntax
The basic syntax of a Sub procedure is:
Sub DisplayMessage()
Console.WriteLine("Welcome to VB.NET")
End Sub
This example defines a Sub named DisplayMessage that prints a message to the console.
Visual Basic Sub Example
Once a Sub is created, you can call it from another procedure such as Main().
Module Program
Sub DisplayMessage()
Console.WriteLine("Learning VB.NET Subs")
End Sub
Sub Main()
DisplayMessage()
End Sub
End Module
In this Visual Basic Sub example, Main() calls DisplayMessage(), which executes the code inside the Sub procedure.
Sub vs Function
Although both are reusable procedures, they serve different purposes.
Sub | Function |
Does not return a value | Returns a value |
Performs an action | Performs a calculation or operation and returns the result |
Declared using Sub | Declared using Function |
Use a Sub when you only need to perform an action, and use a Function when you need to return a value.
Best Practices
Use meaningful names such as DisplayMessage() or PrintReport().
Keep each Sub focused on one specific task.
Reuse Subs instead of duplicating code.
Pass parameters when a Sub needs input instead of relying on global variables.
Learning VB.NET Subs helps you organize your programs into smaller, reusable procedures, making your code easier to read, test, and maintain. Next, continue with VB.NET Classes and Objects to learn how procedures work within object-oriented programming.
Frequently Asked Questions
What is the difference between a Sub and a Function?
A Sub (subroutine) performs an action but does not return a value, while a Function performs an action and returns a value to the caller.
How do I declare a Sub procedure in VB.NET?
Sub procedures are declared using the "Sub" and "End Sub" statements, following the format "Sub ProcedureName(parameters) ... End Sub."
How do I handle code that is too long for one line in VB.NET?
If a statement is too long to fit on a single line, you can break it up by ending the line with an underscore character ( _ ) as a line continuation symbol.
How do I call a Sub procedure in VB.NET?
You can call a Sub procedure by writing its name followed by parentheses containing any required arguments, such as calling DisplayMessage() within the Main() procedure.
Can I pass parameters to a Sub procedure in VB.NET?
Yes, you can pass parameters to a Sub procedure by declaring them inside the parentheses in the Sub statement, which allows you to pass input data instead of relying on global variables.
