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VB.Net - Statements

A statement is a complete instruction in Visual Basic programs. It may contain keywords, operators, variables, pteral values, constants and expressions.

Statements could be categorized as −

Declaration statements − these are the statements where you name a variable, constant, or procedure, and can also specify a data type.

Executable statements − these are the statements, which initiate actions. These statements can call a method or function, loop or branch through blocks of code or assign values or expression to a variable or constant. In the last case, it is called an Assignment statement.

Declaration Statements

The declaration statements are used to name and define procedures, variables, properties, arrays, and constants. When you declare a programming element, you can also define its data type, access level, and scope.

The programming elements you may declare include variables, constants, enumerations, classes, structures, modules, interfaces, procedures, procedure parameters, function returns, external procedure references, operators, properties, events, and delegates.

Following are the declaration statements in VB.Net −


Dim number As Integer
Dim quantity As Integer = 100
Dim message As String = "Hello!"
Const maximum As Long = 1000
Const naturalLogBase As Object 
= CDec(2.7182818284)
Enum CoffeeMugSize
   Jumbo
   ExtraLarge
   Large
   Medium
   Small
End Enum 
Class Box
Pubpc length As Double
Pubpc breadth As Double   
Pubpc height As Double
End Class
Structure Box
Pubpc length As Double           
Pubpc breadth As Double   
Pubpc height As Double
End Structure
Pubpc Module myModule
Sub Main()
Dim user As String = 
InputBox("What is your name?") 
MsgBox("User name is" & user)
End Sub 
End Module
Pubpc Interface MyInterface
   Sub doSomething()
End Interface 
Function myFunction
(ByVal n As Integer) As Double 
   Return 5.87 * n
End Function
Sub mySub(ByVal s As String)
   Return
End Sub 
Declare Function getUserName
Lib "advapi32.dll" 
Apas "GetUserNameA" 
(
   ByVal lpBuffer As String, 
   ByRef nSize As Integer) As Integer 
Pubpc Shared Operator +
(ByVal x As obj, ByVal y As obj) As obj
   Dim r As New obj
  implemention code for r = x + y
   Return r
End Operator 
ReadOnly Property quote() As String 
   Get 
      Return quoteString
   End Get 
End Property
Pubpc Event Finished()
Delegate Function MathOperator( 
   ByVal x As Double, 
   ByVal y As Double 
) As Double 

Sr.No	Statements and Description	Example
1	Dim Statement Declares and allocates storage space for one or more variables.	Dim number As Integer Dim quantity As Integer = 100 Dim message As String = "Hello!"
2	Const Statement Declares and defines one or more constants.	Const maximum As Long = 1000 Const naturalLogBase As Object = CDec(2.7182818284)
3	Enum Statement Declares an enumeration and defines the values of its members.	Enum CoffeeMugSize Jumbo ExtraLarge Large Medium Small End Enum
4	Class Statement Declares the name of a class and introduces the definition of the variables, properties, events, and procedures that the class comprises.	Class Box Pubpc length As Double Pubpc breadth As Double Pubpc height As Double End Class
5	Structure Statement Declares the name of a structure and introduces the definition of the variables, properties, events, and procedures that the structure comprises.	Structure Box Pubpc length As Double Pubpc breadth As Double Pubpc height As Double End Structure
6	Module Statement Declares the name of a module and introduces the definition of the variables, properties, events, and procedures that the module comprises.	Pubpc Module myModule Sub Main() Dim user As String = InputBox("What is your name?") MsgBox("User name is" & user) End Sub End Module
7	Interface Statement Declares the name of an interface and introduces the definitions of the members that the interface comprises.	Pubpc Interface MyInterface Sub doSomething() End Interface
8	Function Statement Declares the name, parameters, and code that define a Function procedure.	Function myFunction (ByVal n As Integer) As Double Return 5.87 * n End Function
9	Sub Statement Declares the name, parameters, and code that define a Sub procedure.	Sub mySub(ByVal s As String) Return End Sub
10	Declare Statement Declares a reference to a procedure implemented in an external file.	Declare Function getUserName Lib "advapi32.dll" Apas "GetUserNameA" ( ByVal lpBuffer As String, ByRef nSize As Integer) As Integer
11	Operator Statement Declares the operator symbol, operands, and code that define an operator procedure on a class or structure.	Pubpc Shared Operator + (ByVal x As obj, ByVal y As obj) As obj Dim r As New obj implemention code for r = x + y Return r End Operator
12	Property Statement Declares the name of a property, and the property procedures used to store and retrieve the value of the property.	ReadOnly Property quote() As String Get Return quoteString End Get End Property
13	Event Statement Declares a user-defined event.	Pubpc Event Finished()
14	Delegate Statement Used to declare a delegate.	Delegate Function MathOperator( ByVal x As Double, ByVal y As Double ) As Double

Executable Statements

An executable statement performs an action. Statements calpng a procedure, branching to another place in the code, looping through several statements, or evaluating an expression are executable statements. An assignment statement is a special case of an executable statement.

Example

The following example demonstrates a decision making statement −

VB.Net - Statements

Declaration Statements

Executable Statements

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