There may be scenarios when you need to execute a block of code numerous times. In general, statements are executed in the following order: the first statement in a function is executed first, then the second, and so on.
Programming languages have a variety of control structures that enable more complex execution routes.
A loop statement allows us to run a statement or group of statements many times. The general form of a loop statement in most programming languages is as follows:
Following are the types of looping statements available in VB.Net:
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Loop Type
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Description
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Do Loop
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It loops through the enclosing block of statements as long as a Boolean condition is True or until the condition becomes True. It might be ended at any time by using the Exit Do statement.
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For...Next
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It repeats a set number of statements, and a loop index counts the number of loop iterations while the loop executes.
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For Each...Next
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It iteratively repeats a set of statements for each element in a collection. This loop is used to access and manipulate all elements in an array or a VB.Net collection.
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While... End While
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As long as a specified condition is True, it will execute a series of statements.
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With... End With
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It's not quite a looping construct. It runs a series of statements that all relate to the same object or structure.
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Nested loops
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You can nest one or more loops within another While, For, or Do loop.
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Loop Control Statements
Control statements in a loop alter the execution sequence. When execution exits a scope, all automated objects produced inside that scope are deleted.
Following control statements are available in VB.Net:
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Control Statement
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Description
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Exit statement
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The loop or select case statement is terminated, and execution is transferred to the statement immediately following the loop or select case.
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Continue statement
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This instructs the loop to skip the rest of its body and immediately retest its condition before reiterating.
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GoTo statement
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Control is passed to the labeled statement. However, using the GoTo statement in your program is not recommended.
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