Is there any way to get unique numbers for a label?

Question

Im writing a lottery code and would like to know if there is anyway to get my 6 numbers in my label to be different

this is my code so far

Public Class frmMain

    Private randGen As New Random



    Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub

    Private Sub btnSelect_Click(sender As Object, e As EventArgs) Handles btnSelect.Click

        Dim intNum1 As Integer
        Dim intNum2 As Integer
        Dim intNum3 As Integer
        Dim intNum4 As Integer
        Dim intNum5 As Integer
        Dim intNum6 As Integer






        intNum1 = randGen.Next(1, 54)
        intNum2 = randGen.Next(1, 54)
        intNum3 = randGen.Next(1, 54)
        intNum4 = randGen.Next(1, 54)
        intNum5 = randGen.Next(1, 54)
        intNum6 = randGen.Next(1, 54)








        lblNumbers.Text = String.Format("{0}, {1}, {2}, {3}, {4}, {5}", intNum1, intNum2, intNum3, intNum4, intNum5, intNum6)





    End Sub


End Class

Answer 1

If you want all 6 numbers to be different, I suggest putting all the possible numbers (1-53 in your example) in a list and picking 6 numbers at random from the list (removing each number from the list when you pick it). You can store the numbers in an array and use String.Join to display them in a label.

Private randGen As New Random 
	
Sub btn_Select_Click(sender As Object, e As EventArgs) Handles btnSelect.Click
	Dim allNumbers As List(Of Integer) = Enumerable.Range(1, 53).ToList 'will be numbers 1-53
	Dim intNum(5) As Integer 
		
	For i As Integer = 0 To 5
		Dim pos As Integer = randGen.Next(0, allNumbers.Count)
		intNum(i) = allNumbers(pos)
		allNumbers.RemoveAt(pos)
	Next
		
	lblNumbers.Text = String.Join(" ", intNum.Select(Function(i) i.ToString))
End Sub

Answer 2

Try this too:

Dim a = Enumerable.Range(1, 53).OrderBy(Function() randGen.Next).Take(6).ToArray

intNum1 = a(0)
intNum2 = a(1)
intNum3 = a(2)
intNum4 = a(3)
intNum5 = a(4)
intNum6 = a(5)

Answer 3

Karodhill,

No matter how you go about doing this, these numbers are repeatable. Don't confuse randomness with uniqueness; the two really have nothing to do with each other.

A GUID is a better choice, but it's letters and numbers and it's much longer than six! If you're sure you want six, then at least keep track of the ones which were selected previously and set your program up to continue generating a new one until it's not in that list.

Do also know though that at some point in time, that list will be "full" and you need to calculate the total possible combinations so to know when you're "done". Otherwise you'll end up in an endless loop; you tell it to continue until it's not in the list and ... there are none to be had.

For what it's worth... :)

---

Still lost in code, just at a little higher level.

:-)

Answer 4

Try this too:

Dim a = Enumerable.Range(1, 53).OrderBy(Function() randGen.Next).Take(6).ToArray

intNum1 = a(0)
intNum2 = a(1)
intNum3 = a(2)
intNum4 = a(3)
intNum5 = a(4)
intNum6 = a(5)

Viorel,

How does that prevent each of them from being the same value?

Maybe I'm missing it?

---

Still lost in code, just at a little higher level.

:-)

Answer 5

@Frank. The code I posted does not repeat any numbers (as I explained in the post); this is a standard way of randomly choosing numbers in the style of a lottery. I don't think Viorel_'s code repeats numbers either.

Answer 6

@Frank. The code I posted does not repeat any numbers (as I explained in the post); this is a standard way of randomly choosing numbers in the style of a lottery. I don't think Viorel_'s code repeats numbers either.

Then please explain to me how his doesn't (I can see that yours won't).

It's "taking" six ... from the random set. What's to prevent one of those from being same value?

I wasn't trying to cast aspersions here! I just don't see how it avoids it.

---

Still lost in code, just at a little higher level.

:-)

Answer 7

@Frank. The code I posted does not repeat any numbers (as I explained in the post); this is a standard way of randomly choosing numbers in the style of a lottery. I don't think Viorel_'s code repeats numbers either.

Oh I do see!

He's ordering them randomly then taking six - so of course each has to be different!

Very clever Viorel! :)

---

Still lost in code, just at a little higher level.

:-)

Answer 8

by unique i mean at the instant the button is pressed, on the same label line none of those will be the same

Answer 9

@Frank. The code I posted does not repeat any numbers (as I explained in the post); this is a standard way of randomly choosing numbers in the style of a lottery. I don't think Viorel_'s code repeats numbers either.

Then please explain to me how his doesn't (I can see that yours won't).

It's "taking" six ... from the random set. What's to prevent one of those from being same value?

I wasn't trying to cast aspersions here! I just don't see how it avoids it.

---

Still lost in code, just at a little higher level.

:-)

No problem Frank.

Answer 10

by unique i mean at the instant the button is pressed, on the same label line none of those will be the same

Then you have two good examples shown here. :)

---

Still lost in code, just at a little higher level.

:-)

Answer 11

Here's one way using nested For loops.  This was tested and it works.  It will select 6 different unique numbers between 1 - 54. 

    Private Sub btnOK_Click(sender As System.Object, e As System.EventArgs) Handles btnOK.Click
        Dim num As Integer, dup As Boolean = False
        Dim randnum As New Random()
        Dim strand As String = ""
        Dim itm As String = ""
        For x As Integer = 1 To 6
            For y As Integer = 1 To 6
                num = randnum.Next(1, 55)
                itm = num.ToString()
                If strand.Contains(itm) Then
                    dup = True
                    x = x - 1
                    Exit For
                End If
            Next y
            If dup = False Then strand &= itm & "  "
            dup = False
        Next x
        lblRandom.Text = strand
    End Sub

Here is another way using the Shuffle Sort algorithm with an array:

    Private Sub btnShuffle_Click(sender As System.Object, e As System.EventArgs) Handles btnShuffle.Click
        Dim mix, temp As Integer
        Dim randnum As New Random
        Dim strand(54) As Integer
        lblRandom.Text = ""
        For x As Integer = 1 To 54
            strand(x) = x
        Next
        For x As Integer = 1 To 54
            mix = randnum.Next(1, 55)
            temp = strand(mix)
            strand(mix) = strand(x)
            strand(x) = temp
        Next
        For x As Integer = 1 To 6
            lblRandom.Text &= strand(x).ToString & "  "
        Next
    End Sub

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Solitaire