Sub Procedure Vs Function in VB.NET

.NET is a software framework that is designed and developed by Microsoft. The first version of the .Net framework was 1.0 which came in the year 2002. In other words, it is a virtual machine for compiling and executing programs written in different languages like C#, VB.Net, etc. 

Sub Procedures:

A subprocedure is a group of VB.NET statements. It begins with a Sub keyword and ends with End Sub keywords. A subprocedure is also called a subroutine. It is used to execute a certain block of statements consists the body of the procedure. It is called explicitly by its name whenever it is required to perform a certain task. It can be called any number of times. The subprocedure returns control to the calling code after performing a task. 

 Structure of Subprocedure:

Sub <subname> [(parameter list)]

Vb statements

End Sub

Example:

Module module1
 Sub SubDivide(ByVal num1 As Integer, 
  ByVal num2 As Integer)
    
    Dim res As Integer
    
    If (num2 <> 0) Then
    res = num1/num2
       Console.WriteLine("Divide by Zero is possible")
    Else
      Console.WriteLine("Divide by Zero is undefined")
    End If
 End Sub
 Sub Main()
    Dim a As Integer
    Dim b As Integer 
    Dim res As Integer
    Console.Write("Enter Number 1")
    a = Console.ReadLine()
    Console.Write("Enter Number 2")
    b = Console.ReadLine()
    SubDivide(a, b)
    
     Console.WriteLine(res)
    
 End Sub
End Module
 

Output:

Function Procedures:

A function procedure is a group of VB.NET statements.  It begins with a Function keyword and ends with an End Function keyword. It is generally used to perform a task and return a value back to the calling code. It may have multiple return points to the calling code. A part from return stamens, End Function, or Exit function also returns control to the calling procedure.   

Structure of Function Procedure:

Function <Functionname> [(parameter list)] As return type

Vb statements

End Function

Example:

Module module1
 Function FunctionDivide(ByVal num1 As Integer, 
   ByVal num2 As Integer) As Integer
    
    Dim res As Integer
    
    If (num2 <> 0) Then
    res = num1/num2
       return res
    Else
      Console.WriteLine("Divide by Zero is undefined")
    End If
 End Function
 Sub Main()
    Dim a As Integer
    Dim b As Integer 
    Dim res As Integer
    Console.Write("Enter Number 1")
    a = Console.ReadLine()
    Console.Write("Enter Number 2")
    b = Console.ReadLine()
    res = FunctionDivide(a, b)
    
     Console.WriteLine(res)
    
 End Sub
End Module

Output:

Comparison between SubProcedure and Function:

Parameters	Sub Procedures	Functions
1	A subprocedure is not associated with an event.	A function is also not associated with an event.
2	A subprocedure is called, whenever it is required to perform certain tasks. It returns control to the calling code after performing a task.	A function is called, whenever a value is required to be returned to the calling code after performing a task.
3	A subprocedure does not return a value to the calling code.	Functions return a value to the calling code.
4	A sub procedure cannot be used with an expression.	Functions are used in an expression.
5	Subprocedure helps to make the code readable, and easy to modify and debug.	In functions, it is not easy to modify and debug the code.
6	Sub procedure is a generalized type of function.	A function is a specific type of procedure
7.	A subprocedure is declared with the keyword Sub.	A function is declared with the keyword Function.