VB.Net - If...Then Statement

It is the simplest form of control statement, frequently used in decision making and changing the control flow of the program execution. Syntax for if-then statement is −

If condition Then 
[Statement(s)]
End If

Where, condition is a Boolean or relational condition and Statement(s) is a simple or compound statement. Example of an If-Then statement is −

If (a <= 20) Then
   c= c+1
End If

If the condition evaluates to true, then the block of code inside the If statement will be executed. If condition evaluates to false, then the first set of code after the end of the If statement (after the closing End If) will be executed.

Flow Diagram

Example

Module decisions
   Sub Main()
      'local variable definition 
      Dim a As Integer = 10

      ' check the boolean condition using if statement 
      If (a < 20) Then
         ' if condition is true then print the following 
         Console.WriteLine("a is less than 20")
      End If
      Console.WriteLine("value of a is : {0}", a)
      Console.ReadLine()
    End Sub
End Module

When the above code is compiled and executed, it produces the following result −

a is less than 20
value of a is : 10