CODEWITHSUNDEEP
vb.netloopsfor-loopnested
Ronnel Yatco
Ronnel Yatco

Reputation: 51

Nested For Loop vb.net

If I would enter 5 to textbox, the answer would be like this

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

then if i would enter 10 or more the answer would be

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
1 2 3 4 5 6
1 2 3 4 5 6 7
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 10

my code:

Private Sub CmdOk_Click()

Dim a, b, c, d, z As Integer
z = TxtInput.Text

For a = 1 To z Step 1
List1.AddItem a
For b = 2 To z Step 1
List1.AddItem a & " " & b
For c = 3 To z step 1
List1.AddItem a & " " & b & " " & c
For d = 4 To z Step 1
List1.AddItem a & " " & b & " " & c & " " & d
Next d
Next c
Next b
Next a

End Sub

Output of my code

Upvotes: 2

Views: 2251

Answers (4)

slek
slek

Reputation: 309

This works. Try this. 

List1.Items.Clear()
    Dim i, j, z As Integer
    Dim x, a As String
    z = TxtInput.Text
    For i = 1 To z
        For j = 1 To i
            x = Convert.ToString(j)
            a = a & " " & x
        Next
        List1.Items.Add(a)
        a = ""
    Next

Upvotes: 0

djv
djv

Reputation: 15772

In one line (edited for clarity)

List1.Items.AddRange(
    Enumerable.Range(1, Integer.Parse(Me.txtInput.Text)).
    Select(Of String)(
        Function(i)
            Return Enumerable.Range(2, i - 1).
                Select(Of String)(Function(i1) i1.ToString()).
                Aggregate(Of String)("1", Function(s1, s2) s1 & " " & s2)
        End Function).ToArray())

As a side-note, this approach is about twice as fast as the other answer, important if the number gets large.

Upvotes: 0

Sifu
Sifu

Reputation: 1082

Why are you making it so complicated?

That is suppose to work :

Private Sub CmdOk_Click()

  Dim z as String = TxtInput.Text
  Dim ListTemporary as String = "1"

  For i = 2 To Integer.parse(z) Step 1
    ListTemporary = ListTemporary & " " & i.ToString()
    List1.AddItem ListTemporary
  Next

End Sub

Upvotes: 2

Suji
Suji

Reputation: 1326

Private Sub CmdOk_Click()     
 ListBox1.Items.Clear() ' clear the list before processing
  Dim s As String = "" ' initialize a string variable
  For i As Integer = 1 To CInt(TextBox1.Text) ' i loop for row counting
  s = "" ' in each itetration clear the s value
  For j As Integer = 1 To i ' for format the string to display in each index
  s = s & j & " " 
  Next
  ListBox1.Items.Add(s) ' add each item in row index
 Next
End Sub

Upvotes: 1

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