There may be a situation when you need to execute a block of code several number of times. In general statements are executed sequentially: The first statement in a function is executed first, followed by the second, and so on.
Programming languages provide various control structures that allow for more complicated execution paths.
A loop statement allows us to execute a statement or group of statements multiple times and following is the general from of a loop statement in most of the programming languages:
VB.Net provides following types of loop to handle looping requirements. Click the following links to check their detail.
| Loop Type | Description |
|---|---|
| Do Loop | It repeats the enclosed block of statements while a Boolean condition is True or until the condition becomes True. It could be terminated at any time with the Exit Do statement. |
| For...Next | It repeats a group of statements a specified number of times and a loop index counts the number of loop iterations as the loop executes. |
| For Each...Next | It repeats a group of statements for each element in a collection. This loop is used for accessing and manipulating all elements in an array or a VB.Net collection. |
| While... End While | It executes a series of statements as long as a given condition is True. |
| With... End With | It is not exactly a looping construct. It executes a series of statements that repeatedly refers to a single object or structure. |
| Nested loops | You can use one or more loop inside any another While, For or Do loop. |
Loop Control Statements:
Loop control statements change execution from its normal sequence. When execution leaves a scope, all automatic objects that were created in that scope are destroyed.
VB.Net provides the following control statements. Click the following links to check their detail.
| Control Statement | Description |
|---|---|
| Exit statement | Terminates the loop or select case statement and transfers execution to the statement immediately following the loop or select case. |
| Continue statement | Causes the loop to skip the remainder of its body and immediately retest its condition prior to reiterating. |
| GoTo statement | Transfers control to the labeled statement. Though it is not advised to use GoTo statement in your program. |