VB.NET Option Explicit

Today I will tell you about using the Option Explicit statement. The Option Explicit has two modes. On and Off mode. If Option Explicit mode in ON , you have to declare all the variable before you use it in the program . If not , it will generate a compile-time error whenever a variable that has not been declared is encountered .If the Option Explicit mode is OFF , Vb.Net automatically create a variable whenever it sees a variable without proper declaration

By default the Option Explicit Statement is always On.

Option Explicit Off
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click
someVariable = "Option Explicit ON"
MsgBox(someVariable)
End Sub
End Class

Here "someVariable" is not declared , because the Option Explicit Of , without any compiler error you can continue the program.

Using Nothing Syntax in VB.NET

When coding in VB.NET you will sometimes want to declare a variable or a string as Nothing. There is a really way to do this and it takes about 1 line of code. Here is how you can do it.

 Sub Main2()
 Dim sString As String = Nothing

 If sString = Nothing Then
     Msgbox("You've got nothing")
 End If

You can also ofcourse combine Nothing with an If-else statement which will help you test to see if the string is actually Nothing.