Visual Basic .NET

Visual Basic .NET (VB.NET) is a multi-paradigm, high level programming language, implemented on the .NET Framework. Microsoft launched VB.NET in 2002 as the successor to its original Visual Basic language.

Visual Basic enables developers to target Windows, Web, and mobile devices. As with all languages targeting the Microsoft .NET Framework, programs written in Visual Basic benefit from security and language interoperability.

Syntax

VB.NET uses statements to specify actions. The most common statement is an expression statement, consisting of an expression to be evaluated, on a single line. As part of that evaluation, functions or subroutines may be called and variables may be assigned new values. To modify the normal sequential execution of statements, VB.NET provides several control-flow statements identified by reserved keywords. Structured programming is supported by several constructs including one conditional execution construct (If … Then … Else … End If) and three iterative execution (loop) constructs (Do Until … Loop, For … To, and For Each) .

The For … To statement has separate initialization and testing sections, both of which must be present. (See examples below.) The For Each statement steps through each value in a list.

In addition, in Visual Basic .NET:

  • There is no unified way of defining blocks of statements. Instead, certain keywords, such as "If … Then" or "Sub" are interpreted as starters of sub-blocks of code and have matching termination keywords such as "End If" or "End Sub".
  • Statements are terminated either with a colon (":") or with the end of line. Multiple line statements in Visual Basic .NET are enabled with " _" at the end of each such line. The need for the underscore continuation character was largely removed in version 10 and later versions.
  • The equals sign("=") is used in both assigning values to variable and in comparison.
  • Round brackets (parentheses) are used with arrays, both to declare them and to get a value at a given index in one of them. Visual Basic .NET uses round brackets to define the parameters of subroutines or functions.
  • A single quotation mark ('), placed at the beginning of a line or after any number of space or tab characters at the beginning of a line, or after other code on a line, indicates that the (remainder of the) line is a comment.