Have to create a lottery program, getting the random numbers and such easily enough. However I'm stumped. Essentially I have 2 buttons. One to display a checked list box with numbers 1-100, along with the 5 lotto numbers. I have a 2nd button that checks 2 things, to make sure that more than 5 numbers are not checked matching numbers. I'm lost on how to check for a match between the selected numbers between the RNG numbers.
Public Class Form1
Private Sub displayBtn_Click(sender As Object, e As EventArgs) Handles displayBtn.Click
Dim lottoNumbers(5) As Integer
Dim counter As Integer = 0
Dim number As Integer
Dim randomGenerator As New Random(Now.Millisecond)
'This will randomly select 5 unique numbers'
Do While counter < 5
number = randomGenerator.Next(0, 98)
If Array.IndexOf(lottoNumbers, number) = -1 Then
lottoNumbers(counter) = number
counter += 1
End If
Loop
'Display the lottery numbers in the label.'
Label1.Text = String.Empty
Array.Sort(lottoNumbers)
For Each num As Integer In lottoNumbers
Label2.Text = "Lottery Numbers"
Label1.Text &= CStr(num) & " "
Next num
For x = 0 To 98
CheckedListBox1.Items.Add(x + 1)
Next
End Sub
Private Sub checkBtn_Click(sender As Object, e As EventArgs) Handles checkBtn.Click
Dim count As Integer = 0
Dim x As Integer
'Checks to see if user checked more than 5'
For x = 0 To CheckedListBox1.Items.Count - 1
If (CheckedListBox1.CheckedItems.Count > 5) Then
MessageBox.Show("You cannot select more than 5 numbers.")
Return
Else
If (CheckedListBox1.GetItemChecked(x) = True) Then
count = count + 1
ListBox1.Items.Add(CheckedListBox1.Items(x))
End If
End If
Next
End Sub
Related
I'm developing a program that asks the user to input 5 numbers. The lowest of the 5 numbers will be dropped, and then the other 4 numbers are to be averaged.
I'm quite new to VB, but I believe I'm currently on the right path here...
I've sorted the array to help identify the lowest number, but I do not know how to exclude the lowest number and to then average the other remaining 4.
Here is my code so far:
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim IntArr(4) As Integer
Dim i As Integer
For i = 1 To 5
IntArr(4) = InputBox("Enter Number" & i)
Next
Array.Sort(IntArr)
'textbox1.text = ???
End Sub
End Class
Can anyone please assist or at least point me in the right direction?
In keeping with the spirit of your code, something like the following would work.
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim IntArr(4) As Integer
Dim OutArr(3) As Integer
For i = 0 To 4
IntArr(i) = InputBox("Enter Number " & i)
Next
Array.Sort(IntArr)
Array.Copy(IntArr, 1, OutArr, 0, 4) 'exclude the lowest number
TextBox1.Text = OutArr.Average()
End Sub
End Class
Using built in LINQ functions
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim numberOfItems = 5
Dim numberOfItemsToRemove = 1
Dim inArray(numberOfItems - 1) As Integer
Dim outArray(numberOfItems - 1 - numberOfItemsToRemove) As Integer
Dim i As Integer
For i = 0 To numberOfItems - 1
While Not Integer.TryParse(InputBox("Enter Number " & i + 1), inArray(i))
MessageBox.Show("Invalid input!")
End While
Next
outArray = inArray.OrderBy(Function(j) j).Skip(numberOfItemsToRemove).ToArray()
MessageBox.Show(
String.Format(
"Input: [{0}], Output: [{1}], average: {2:0.0}",
String.Join(", ", inArray),
String.Join(", ", outArray),
outArray.Average))
End Sub
Your code as it is above will continue to simply change the value of index 4 with each box if I'm not mistaken. I would do something like this (I will use your variable names for your convenience).
Button1_Click(procedure junk that is auto-inserted)
Dim intArr(4) As Integer
Dim OutArr(3) As Integer
Dim intCounter, intAverage, intLowest, intLowIndex As Integer
'populate all indexes of intArr()
For intCounter = 0 to 4
intArr(intCounter) = InputBox("Please enter a number.")
Next intCounter
intCounter = 1 'reset counter for check
intLowest = intArr(intLowIndex) 'start with index 0
'find lowest number and its index
For intCounter = 1 to 4
If intLowest > intArr(intCounter) Then 'defaults to previous
intLowest = intArr(intCounter)
intLowIndex = intCounter
End If
Next intCounter
intCounter = 0 'reset counter again for possible For...Next loops
Select Case intLowIndex
Case = 0
For intCounter = 0 to 3
OutArr(intCounter) = intArr(intCounter + 1)
Next intCounter
Case = 1
OutArr(0) = intArr(0)
OutArr(1) = intArr(2)
OutArr(2) = intArr(3)
OutArr(3) = intArr(4)
Case = 2
OutArr(0) = intArr(0)
OutArr(1) = intArr(1)
OutArr(2) = intArr(3)
OutArr(3) = intArr(4)
Case = 3
OutArr(0) = intArr(0)
OutArr(1) = intArr(1)
OutArr(2) = intArr(2)
OutArr(3) = intArr(4)
Case = 4
For intCounter = 0 to 3
OutArr(intCounter) = intArr(intCounter)
Next intCounter
End Select
intAverage = (OutArr(0) + OutArr(1) + OutArr(2) + OutArr(3)) / 4
'insert your preferred method to display OutArr() and intAverage
This question already has answers here:
What is a NullReferenceException, and how do I fix it?
(27 answers)
Closed 7 years ago.
I have a program that creates a list of 25 random numbers from 0 to 1,000. I have to buttons the first button will load a list box with the random numbers and the second button will sort the list of numbers from the smallest to largest which is where I implemented bubble sort code. Now the other list box that is supposed to hold the sorted numbers doesn't work properly it only shows one number instead of all of them.
Here is my code:
Option Strict On
Public Class Form1
Dim rn As Random = New Random
Dim Clicked As Long = 0
Dim numbers, sort As Long
Private Sub GenerateBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles GenerateBtn.Click
Clicked += 1
For x = 0 To 25
numbers = rn.Next(0, 1000)
RandomBox.Items.Add(numbers)
If Clicked >= 2 Then
RandomBox.Items.Clear()
Clicked = 1
End If
Next
End Sub
Private Sub SortBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SortBtn.Click
Dim Sorted() As Long = {numbers}
Dim Swapped As Boolean
Dim endOfArray As Integer = Sorted.Length - 1
Dim Tmp As Byte
While (Swapped)
Swapped = False
For I = 0 To endOfArray - 1
If Sorted(I) > Sorted(I + 1) Then
Tmp = CByte(Sorted(I))
Sorted(I) = Sorted(I + 1)
Sorted(I + 1) = Tmp
Swapped = True
End If
endOfArray = endOfArray - 1
Next
End While
SortBox.Items.Clear()
For I = 0 To Sorted.Count - 1
SortBox.Items.Add(Sorted(I))
Next
End Sub
End Class
Change your:
Dim Sorted() As Long = {numbers}
to
Sorted(x) = numbers
edit: Since you changed your code. You need to put back in the line that loads the Sorted Array.
For x = 0 To 25
numbers = rn.Next(0, 1000)
RandomBox.Items.Add(numbers)
Sorted(x) = numbers
If Clicked >= 2 Then
RandomBox.Items.Clear()
Clicked = 1
End If
Next
and remove the:
Dim Sorted() As Long = {numbers}
from the second part and put this declaration back in the beginning like you had:
Dim Sorted(26) as Long
The way you have will only show the latest random number. It is not any array but a single entity. Therefore only the latest will be add into the array. You need to load each number into the array as you create each one. Thus the (x) which loads it into position x.
You didn't use any arrays at all in your project...you're using the ListBox as your storage medium and that's a really bad practice.
I recommend you set it up like this instead:
Public Class Form1
Private rn As New Random
Private numbers(24) As Integer ' 0 to 24 = 25 length
Private Sub GenerateBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles GenerateBtn.Click
For x As Integer = 0 To numbers.Length - 1
numbers(x) = rn.Next(0, 1000)
Next
' reset the listbox datasource to view the random numbers
RandomBox.DataSource = Nothing
RandomBox.DataSource = numbers
' empty out the sorted listbox
SortBox.DataSource = Nothing
End Sub
Private Sub SortBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SortBtn.Click
' make a COPY of the original array that we will sort:
Dim sorted(numbers.Length - 1) As Integer
Array.Copy(numbers, sorted, numbers.Length)
Dim Swapped As Boolean = True
Dim endOfArray As Integer = Sorted.Length - 1
Dim Tmp As Integer
While (Swapped)
Swapped = False
For I As Integer = 0 To endOfArray - 1
If sorted(I) > sorted(I + 1) Then
Tmp = sorted(I)
sorted(I) = sorted(I + 1)
sorted(I + 1) = Tmp
Swapped = True
End If
Next
endOfArray = endOfArray - 1
End While
' reset the listbox datasource to view the sorted numbers
SortBox.DataSource = Nothing
SortBox.DataSource = sorted
End Sub
End Class
Also, note that you were decrementing endOfArray inside your for loop. You should only decrement it after each pass; so outside the for loop, but inside the while loop.
Additionally, you were using a Tmp variable of type Byte, but generating numbers between 0 and 999 (inclusive). The Byte type can only hold values between 0 and 255 (inclusive).
Your Bubble Sort implementation was very close to correct!
Hello everyone so i'm trying to find the prime numbers of any input. I want them to be in a listbox and the input in a text box. I would like to use two arguments but i don't know how to. this is the code i have i need dire help. I am not the best at visual basic i just need some guidance. My code isn't working but display a drop down box when i press display.
Public Class Form1
Private Sub Button3_Click_1(sender As Object, e As EventArgs) Handles Button3.Click
Dim prim As Integer
Dim test As Integer
Dim imPrime As Boolean = False
prim = CInt(txtNum.Text)
test = prim
If prim = 1 Then
imPrime = False
MessageBox.Show("Enter a number greater than one please")
Else
Do While prim >= 2
For i As Integer = 2 To prim
If prim Mod i = 0 Then
imPrime = False
Exit For
Else
imPrime = True
lstPrime.Items.Add(prim)
End If
Next
Loop
End If
If imPrime = True Then
lstPrime.Items.Add(prim)
End If
End Sub
End Class
This is my fastest VBA code to generate prime numbers between two numbers.
The generated prime numbers are put in clipboard. You will need to open
your ms office word and type Ctrl+V to view all the generated prime numbers.
Sub generateprimenumbersbetween()
Dim starting_number As Long
Dim last_number As Long
Dim primenumbers As Variant
Dim a As Long
Dim b As Long
Dim c As Long
starting_number = 1 'input value here
last_number = 1000000 'input value here
primenumbers = ""
For a = starting_number To last_number
c = Round(Sqr(a)) + 1
For b = 2 To c
If a = 1 Or (a Mod b = 0 And c <> b) Then
Exit For
Else
If b = c Then
primenumbers = primenumbers & " " & a
Exit For
End If
End If
Next b
Next a
Dim answer As DataObject
Set answer = New DataObject
answer.SetText primenumbers
answer.PutInClipboard
End Sub
I think the while loop is not working as you intend. You need two loops, the first one counting up to the possible prime, and an inner one counting up to the counter in the outer loop.
You can find examples everywhere... here's one implemented in C#, but since your question was specifically about a listbox, I've translated it to VB.
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
calculatePrimes()
End Sub
Private Sub calculatePrimes()
Dim prim As Integer
Dim count As Integer = 0
prim = CInt(Me.TextBox1.Text)
If prim < 3 Then
MsgBox("Please enter a bigger number")
Return
End If
Me.ListBox1.Items.Clear()
For i As Integer = 1 To prim
Dim isPrime As Boolean = True
For j As Integer = 2 To i
If (i Mod j <> 0) Then count = count + 1
Next
If count = (i - 2) Then Me.ListBox1.Items.Add(i)
count = 0
Next
End Sub
End Class
(This assumes you have a textbox for input called TextBox1 and a listbox for display called ListBox1)
So I am working on a program that will ask for the number of assignments, say 20, then run through a loop that many times asking for the total points earned on each assignment as well as the total points possible to get the final grade. For example if the user put in 2 assignments with assignment 1 earning 48 points out of 50 and assignment 2 earning 35 points out of 40 the program would display the grade as 92.
So far here is what I have:
Public Class Form1
Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
Me.Close()
End Sub
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click
Dim amountAssignments As Integer
Dim pointsEarned As Integer = 0
Dim pointsEarnedTotal As Integer = 0
Dim pointsPossible As Integer = 0
Dim pointsPossibleTotal As Integer = 0
Dim Assignment As Integer = 1
Integer.TryParse(txtAmount.Text, amountAssignments)
Do Until Assignment > amountAssignments
txtAmount.Text = String.Empty
lblAmount.Text = "Enter Points Given on Assignment " & Assignment & ":"
Integer.TryParse(txtAmount.Text, pointsEarned)
pointsEarnedTotal = pointsEarnedTotal + pointsEarned
lblAmount.Text = "Enter Points Possible on Assignment " & Assignment & ":"
Integer.TryParse(txtAmount.Text, pointsPossible)
pointsPossibleTotal = pointsPossibleTotal + pointsPossible
Assignment = Assignment + 1
Loop
lblAmount.Text = "Enter the amount of Assignments: "
lblGrade.Text = (pointsEarnedTotal / pointsPossibleTotal)
End Sub
End Class
syntax is correct but when the program is run and the number of assignments put in and calculate entered the program displays the grade as NaN with no other input requested.
Could use another set of eye(s) to look over this and tell me where i screwed up logically.
Thank you in advance!
This program seems to not have some sort of user intervention when the loop starts. What I would do is surely have the user enter the amount of assignments on the textbox and then from there would ask the user to enter marks from an input box separated by a slash e.g I enter 45/50 so after input the program finds the index of "/",all characters before the '/' are the pointsEarned and can be added to the pointsEarnedTotal while all the characters after the '/' are placed in the pointsPossible and added to the pointsPossibleTotal
Try this and tell me how it goes...give me points if it works
` Private Sub butGetMarks_Click(sender As System.Object, e As System.EventArgs) Handles butGetMarks.Click
Dim assignments As Integer = 0
Dim totalAssignments As Integer
Integer.TryParse(txtAssignments.Text, totalAssignments)
Dim pointsEarned As Double = 0
Dim pointsEarnedTotal As Double = 0
Dim possibleEarned As Double = 0
Dim possibleEarnedTotal As Double = 0
Dim temp As String
For i As Integer = 1 To totalAssignments
temp = InputBox("Enter marks per assignment separated by /")
Dim i1 As Integer
i1 = temp.IndexOf("/") 'read index of /
pointsEarned = temp.Substring(0, i1) 'read from start until / character
possibleEarned = temp.Substring(i1 + 1) 'read from after / character onwards
'add to totals
possibleEarnedTotal += possibleEarned
pointsEarnedTotal += pointsEarned
Next i
MessageBox.Show(pointsEarnedTotal & "/" & possibleEarnedTotal)
End Sub`
This program suppose to sort records(in arySort) in ascending order by last name(index 1 in aryTemp and aryTemp2) and place the result in the list box over the old, preloaded, unsorted records.
It sorts them strangely, I have to click multiple times the Ascending button to get the actual sort result that I suppose to get from clicking the button once.
Why doesn't it sort items with a single mouse click?
The source:
Public Class Form1
Dim FILE_NAME As String = "Students.txt"
Dim numberOfRecords As Integer 'total number of records
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
If System.IO.File.Exists(FILE_NAME) = True Then
Dim objReader As New System.IO.StreamReader(FILE_NAME)
Do While objReader.Peek() <> -1
lstBox.Items.Add(objReader.ReadLine)
numberOfRecords += 1
Loop
objReader.Close()
End If
End Sub
Private Sub btnAscending_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAscending.Click
'load all students into array
Dim arySort(numberOfRecords - 1) As String
Dim aryTemp() As String 'holds first record's last name
Dim aryTemp2() As String 'holds second record's last name
For i = 0 To numberOfRecords - 1
arySort(i) = lstBox.Items(i)
Next
Dim temp As String 'holds temporary record
Dim k As Integer
For i = 0 To arySort.Length - 2
aryTemp = Split(arySort(i), " ")
For k = i + 1 To arySort.Length - 1
aryTemp2 = Split(arySort(k), " ")
If aryTemp(1) < aryTemp2(1) Then
temp = arySort(k)
arySort(k) = arySort(i)
arySort(i) = temp
End If
Next
Next
lstBox.Items.Clear()
numberOfRecords = 0
For i = 0 To arySort.Length - 1
lstBox.Items.Add(arySort(i))
numberOfRecords += 1
Next
End Sub
End Class
If you just need to sort your list (as you say in the comment), don't implement your own sort mechanism but use the one of .NET:
' Define how we want to compare items '
Function compareByLastName(ByVal item1 As String, ByVal item2 As String) As Integer
Return String.Compare(item1.Split(" ")(1), item2.Split(" ")(1))
End Function
Private Sub btnAscending_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAscending.Click
' load all students into array '
Dim arySort(numberOfRecords - 1) As String
For i = 0 To numberOfRecords - 1
arySort(i) = lstBox.Items(i)
Next
' Use built-in .NET magic '
Array.Sort(arySort, AddressOf compareByLastName)
' Write the values back into your list box '
lstBox.Items.Clear()
numberOfRecords = 0
For i = 0 To arySort.Length - 1
lstBox.Items.Add(arySort(i))
numberOfRecords += 1
Next
End Sub
This uses the built-in quicksort algorithm of the .NET class library. Here's the documentation of the method we are using: Array.Sort(T(), Comparison(Of T)).
compare with my working bubble sort:
Public Sub BubbleSort(ByVal arr() As Integer)
Dim flag As Boolean = False
For i As Integer = 0 To arr.Length - 1
For j As Integer = 0 To arr.Length - 2 - i
If arr(j + 1) < arr(j) Then
flag = True
Dim temp As Integer = arr(j)
arr(j) = arr(j + 1)
arr(j + 1) = temp
End If
Next
If flag = False Then Return ' no swaps =>already sorted
Next
End Sub
I see a two major issues with your algorithm:
It's not bubble sort. Bubble sort swaps adjacent elements, i.e., it swaps i with i+1. You, on the other hand, swap some element i with the first j > i where name(i) < name(j). Maybe you should show us, in pseudo code, which algorithm you are actually trying to implement?
aryTemp contains element i and aryTemp2 contains some element j > i. Why do you swap the elements if aryTemp(1) < aryTemp2(1)? Isn't that already the correct order if you want your elements to be sorted ascending?