In Visual Basic, For loop is useful to execute a statement or a group of statements repeatedly until the defined condition returns true.
Generally, For loop is useful in Visual Basic applications to iterate and execute the certain block of statements repeatedly until the specified number of times.
Following is the syntax of defining the For loop in Visual Basic programming language.
For variable As [Data Type] = start To end
// Statements to Execute
Next
If you observe the above syntax, we defined For loop with different parameters. Here, the variable parameter is required in the For statement and it must be numeric. The Data Type is optional and it is useful to define the data type for the variable. The start and end parameters are required to define the initial and final value of a variable.
Following is the pictorial representation of For loop process flow diagram in Visual Basic programming language.
Now, we will see how to use For loop in Visual Basic programming language with examples.
Following is the example of using For loop in Visual Basic programming language to iterate or loop through a particular list of statements.
Module Module1
Sub Main()
For i As Integer = 1 To 4
Console.WriteLine("i value: {0}", i)
Next
Console.WriteLine("Press Enter Key to Exit..")
Console.ReadLine()
End Sub
End Module
If you observe the above code, we defined a For loop to iterate over 4 times to print the value of variable i and following are the main parts of For loop.
When we execute the above Visual Basic program, we will get the result like as shown below.
If you observe the above result, For loop executed for 4 times and printed the variable i value for 4 times.
In Visual Basic, by using Exit keyword we can stop the execution of For loop statement based on our requirements.
Following is the example of stopping the execution of For loop using Exit statement.
Module Module1
Sub Main()
For i As Integer = 1 To 4
If i = 3 Then Exit For
Console.WriteLine("i value: {0}", i)
Next
Console.WriteLine("Press Enter Key to Exit..")
Console.ReadLine()
End Sub
End Module
If you observe the above code, we used Exit statement to exit from For loop whenever the variable i value equals to 3.
When we execute the above Visual Basic program, we will get the result like as shown below.
If you observe the above result, whenever the variable i value equals to 3, then automatically the For loop execution has stopped.
This is how we can we use Exit statement in For loop to terminate the execution of For loop based on our requirements.
In visual basic, we can create one For loop within another For loop based on our requirements. Following is the example of creating a nested For loop in Visual Basic.
Module Module1
Sub Main()
For i As Integer = 1 To 4
For j As Integer = i To 3 - 1
Console.WriteLine("i value: {0}, j value: {1}", i, j)
Next
Next
Console.WriteLine("Press Enter Key to Exit..")
Console.ReadLine()
End Sub
End Module
If you observe the above example, we created a For loop within another loop and printing the values based on our requirements.
When we execute the above Visual Basic program, we will get the result like as shown below.
This is how we can create the nested For loops in our Visual Basic programming language based on our requirements.