Visual Basic® 2008 Programmer's Reference

Appendix E. Control Statements

Control statements tell an application which other statements to execute under a particular set of circumstances. They control the path that execution takes through the code. They include statements that tell the program to execute some statements but not others and to execute certain statements repeatedly.

The two main categories of control statements are decision statements and looping statements. The following sections describe the decision and looping statements provided by Visual Basic .NET.

Decision Statements

A decision statement represents a branch in the program. It marks a place where the program can execute one set of statements or another or possibly no statements at all. These include If, Choose, and Select Case statements.

Single-Line If Then

A single-line If Then statement tests a condition and, if the condition is true, executes a piece of code. The code may include more than one simple statement separated by a colon.

Optional Else If clauses let the program evaluate other conditions and execute corresponding pieces of code. A final optional Else clause lets the program execute a piece of code if none of the previous conditions is true.

The syntax is as follows:

If condition Then statement

If condition Then statement1 Else statement2

If condition1 Then statement1 Else If condition2 Then statement2

Else statement3

If condition Then statement1 : statement2

If condition Then statement1 : statement2 Else statement3 : statement4

Complicated single-line ...