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.
VB.Net provides following types of loop to handle looping requirements.
| 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. |
| 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.
| 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. |
