A nested loop is a loop inside a loop. The loops do not have to be the same type. There can be a For loop inside a While loop; a For loop inside a For loop, etc. The inner loop is executed in its entirety for each execution of the outer loop.
The illustration shows a design created using nested loops. The outer loop generates values for Num from 1 to 10.. The inner loop generates values for P from 2 to 4 and displays Math.Pow(Num,P) All of the values for one row are concatenated and displayed at the end of the inner loop. The statement to generate Num (in the outer loop) is executed 10 times, but the statement to compute power (in the inner loop) is executed 30 times!
'Programmer: Janet Joy 'Nested loops Public Class Form1 Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load Dim Num, P As Integer Dim S As String For Num = 1 To 10 S = "" & Num & " : " For P = 2 To 4 S = S & Math.Pow(Num, P) & " " Next ListBox1.Items.Add(S) Next End Sub End Class
