I have a text file and I wish to make code that puts the numbers into an array.
The program is required to read the data for each member from the text file. The program then uses this data to find then display the biggest value. The names of every member who has a value more than 70% of the largest is to be written on an empty text file so that the file can be printed out later.
Nikolai,Bryant,145.6
Susan,Brown,34.2
Teressa,Jones,398.5
Martin,Daly,256.9
Ross,Durrant,409.0
Greg,Watson,99.2
Wendy,Russell,87.4
Pamela,Adkins,73.6
Ian,Hunter,385.7
James,Kerr,505.2
Lesley,Wallace,68.4
Kim,Pettigrew,256.4
Steven,Johnstone,23.4
Ali,Hussain,12.1
Hasan,Abbas,302.0
Jacek,Nowak,199.9
Mirka,Kowalski,176.8
Rudo,Hyper,120.2
Tisa,Sullivan,484.2
Albert,Nvodo,385.8
So far all I have is this:
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim FILE_NAME As String = "H:\S5\Computing\Programming\members.txt"
Dim objReader As New System.IO.StreamReader(FILE_NAME)
End Sub
End Class
You will need to add Imports System.IO at the top of you code file. This has a File class which contains the .ReadAllLines method. This method will return an array of all the lines in the text file.
'String.Split' will return an array of of the fields in the line which were delimited (separated) by a comma. The small c after "," tells the compiler that this is Char which what the .Split method expects.
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Dim FILE_NAME As String = "H:\S5\Computing\Programming\members.txt"
Dim lines = File.ReadAllLines(FILE_NAME)
'Declare an array to hold your numbers VB arrays are declared arr(UBound)
'UBound is upper bound referring to highest index
'The highest index would be 1 less the lenght because indexes start at 0
Dim numbers(lines.Length - 1) As Single
Dim index As Integer 'Will be the index for the numbers array
'From the lines array we can loop through each line
For Each s As String In lines
Dim fields = s.Split(","c)
'Your fields array will have 3 elements, a first name at position (index) 0, last name at 1 and number at 2
'You only want the number - but it is not a number yet, it is still a string
'So we do a CSng to change it to a Single
numbers(index) = CSng(fields(2))
index += 1 'shortcut way to write index = index + 1
Next
For Each n As Single In numbers
Debug.Print(n.ToString)
Next
End Sub
The .TexFieldParser suggested by #jmcilhinney in comments has some extra features which would come in handy but this should get you started.
Related
Public Class Form1
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
TextBox2.Text = TextBox1.Text ^ 2
End Sub
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
TextBox1.Text = Nothing
TextBox2.Text = Nothing
End Sub
End Class
The code above outputs squares of any single values input in textbox1 but i need some help in inputting a couple of values separated by commas and then output the squares of those individual values eg 3,4 the output 9,16
I'm not going to do it all for you, because this looks like homework, but here are some pointers:
TextBox2.Text = TextBox1.Text ^ 2
1) Turn on Option Strict, by placing Option Strict On at the top of your code file or by putting it in the project properties Compile tab. This will help you be more rigorous with your coding. Here you're taking a string (TextBox1.Text) and having VB auto convert it to a number (which might fail), squaring it, and then auto converting it back to a string to store in TextBox2.Text. This is bad news all round; always be crystal clear in your own mind and explicit in your coding about the difference between various data types.A string containing numbers is not the same thing as a number!
2) Rename your textboxes after you drop them on a form. Nothing is more frustrating than to read a block of code where the variable names are irrelevant garbage. You will find this when you come back to some complex code in 6 months and think "what the..."; renaming a textbox so it is called resultTextBox or inputTextBox takes seconds and makes your code instantly more comprehensible to both you and anyone you call in to help out with it
separated by commas
The following line of code will split a string into an array of strings, on comma:
Dim csv = "3,6"
Dim arr = csv.Split(","c)
Console.WriteLine(arr(0)) 'prints 3
Console.WriteLine(arr(1)) 'prints 6
The following line of code will convert a string to an integer:
Dim s = "3"
Dim i = Convert.ToInt32(s)
Maths operations can now be performed on it
i = i * i 'square it
The following line of code will turn an integer into a string:
Dim i as Integer = 3
Dim s as String = i.ToString() 's is now "3"
The following line of code will loop through an array, appending the values in the array to a string variable, and adding commas. Finally it trims off the excess trailing comma
Dim s as New String
For Each x as String in arr
s = s & x & ","
Next x
s = s.TrimEnd(","c)
Here is another way too, using the String.Join helper method:
Dim s as String = String.Join(","c, arr)
I need to extract text from a text file starting with the order number(eg. Order1) and ending with an empty line with all other lines between the order number and the empty line extracted as well for a query. Really have no idea how to go about this so any help is greatly appreciated!
so the file name is "CustomerDetails.txt" and I'd imagine the code would look something like this
If IO.File.Exists("CustomerDetails.txt") Then
Dim inFile As IO.StreamReader = IO.File.OpenText(“CustomerDetails.txt")
End If
and then taking for example "order1" in that text file until the blank space and displaying that is a list box
"Really have no idea how to go about this "
The thinking could go like this...
A text file has a string in it.
I could look up the String class in .net and see if there are any methods that could help me.
Search for "String class in .net"
Looks like we can use a combination of String.IndexOf(String, Int32) and String.Substring(Int32, Int32)
Find the IndexOf your order. The string will be the order "Order1" and we will start looking at index 0 so the Int32 will be 0. Then find the end index. Start looking at the index we just found and stop at the first blank line. We can get the length required by the `.Substring method by subtracting the start index from the end index. Now we can extract the text of Order 1 with the substring method.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim OrderText As String = "Order 1" 'this could be set with TextBox1.Text
'Get the string out of the file
Dim s As String = File.ReadAllText("CustomerDetails.txt")
'Find the index of the order, this overload assumes start index is 0
Dim startIndex As Integer = s.IndexOf(OrderText) 'starts lookint at beginning
'Find the index of the first blank line after the startIndex
'2 new lines make a bland line
Dim endIndex As Integer = s.IndexOf(Environment.NewLine & Environment.NewLine, startIndex)
'Return the string that stars at startIndex with a length of end minus start
Dim Order As String = s.Substring(startIndex, endIndex - startIndex)
'I am going to guess that the details of the order are on separate lines
Dim lines() As String = Order.Split(New String() {Environment.NewLine}, StringSplitOptions.None)
For Each line As String In lines
ListBox1.Items.Add(line)
Next
End Sub
The text file contains the following: inside the [], anything inside () was not in the text file, just for clarification
[1(ID)
Jimmy(First name)
Paul (Last name)
78 (marks1)
80 (marks2)
92 (marks3)
2
Ben
James
67
82
73
]
I created a structure that holds student details including their name, id, marks in each subject.
Private Structure StudInfo
Public FName As String
Public LName As String
Public StudentId As Integer
Public ScMark As Integer
Public EnMark As Integer
Public MaMark As Integer
The program needs to read the first six elements in a row, storing each element into the corresponding structure type, then let it become the first element of an array"students()", and then next six elements, let it become the second element of that array. I have no idea how to use loops to do that.
Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
'create an array that hold student details
Dim Students() As StudInfo
' read from text file
Dim FileNum As Integer = FreeFile()
Dim TempS As String = ""
Dim TempL As String
FileOpen(FileNum, "some.text", OpenMode.Input)
Do Until EOF(FileNum)
TempL = LineInput(FileNum)
TempS = TempL + vbCrLf
Loop
End Sub
Thank you.
You have to use a BinaryReader (which takes a IO.Stream as it's constructor), then you can read the data type you want, into the variable you want.
The problem you will have is the data will not be searchable (ie. you cannot read the 30th record, unless you physically read the first 29, because the strings are of variable length, and therefore the record is variable length), this also applies to modifying a record (you cant make it bigger, because it will overwrite the next record).
The answer is to work with fixed length records, or field offsets or fixed length strings. Then you will have a records of predictable size, and you can determine the amount of records by dividing the file length by the record size.
Hope this helps.
You could try something like this:
Public Class Form1
Private Students As New List(Of StudInfo)
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Students.Clear()
Dim fileName = "c:\some folder\directory\someFile.txt"
Using sr As New System.IO.StreamReader(fileName)
Dim value As Integer
Dim strValue As String
While Not sr.EndOfStream
Try
Dim student As New StudInfo
strValue = sr.ReadLine().Trim("[]")
If Integer.TryParse(strValue, value) Then
student.StudentId = value
Else
MessageBox.Show("Error Converting StudentID to Integer")
Exit Sub
End If
student.FName = sr.ReadLine().Trim("[]")
student.LName = sr.ReadLine().Trim("[]")
strValue = sr.ReadLine().Trim("[]")
If Integer.TryParse(strValue, value) Then
student.ScMark = value
Else
MessageBox.Show("Error Converting ScMark to Integer")
Exit Sub
End If
strValue = sr.ReadLine().Trim("[]")
If Integer.TryParse(strValue, value) Then
student.EnMark = value
Else
MessageBox.Show("Error Converting EnMark to Integer")
Exit Sub
End If
strValue = sr.ReadLine().Trim("[]")
If Integer.TryParse(strValue, value) Then
student.MaMark = value
Else
MessageBox.Show("Error Converting MaMark to Integer")
Exit Sub
End If
Students.Add(student)
Catch ex As Exception
MessageBox.Show("Error reading file. All records may not have been created.")
End Try
End While
MessageBox.Show("Done!")
End Using
End Sub
Private Class StudInfo
Public FName As String
Public LName As String
Public StudentId As Integer
Public ScMark As Integer
Public EnMark As Integer
Public MaMark As Integer
End Class
End Class
It depends a bit on the exact format of your text file.
If the file only contains the data for the two students (no brackets or blank lines), then all you need to do is to open the file and read 6 lines, add the data to your structure. and read the next 6 lines. If you have an undetermined number of students in the text file, then you would be better using a List. Other wise you're goiing to have to use extra processing time to Redim the array each time you want to add a student and keep track of the array size an all sorts of messing around.
However. Lets go with the most straightforward answer and assume your data has no brackets or blank lines and that there are only two students.
This code should work just fine. If you have a different definite number of students, then you will need to change the size of the Students array.
I'm also assuming that the data is correctly formatted and there are no non-numeric characters are in the lines where there shouldn't be.
Private Sub ReadStudentInfo()
'create an array that hold student details
Dim Students(2) As StudInfo
Dim index As Integer = 0
' read from text file
Dim datafile As New StreamReader("some.text")
Do Until datafile.EndOfStream
Dim tempStudent As StudInfo
With tempStudent
Integer.TryParse(datafile.ReadLine, .StudentId)
.FName = datafile.ReadLine
.LName = datafile.ReadLine
Integer.TryParse(datafile.ReadLine, .ScMark)
Integer.TryParse(datafile.ReadLine, .EnMark)
Integer.TryParse(datafile.ReadLine, .MaMark)
End With
Students(index) = tempStudent
index = index + 1
Loop
End Sub
If your text file does contain blank lines, just insert
datafile.ReadLine()
between each line of data - like this
Integer.TryParse(datafile.ReadLine, .ScMark)
datafile.ReadLine()
Integer.TryParse(datafile.ReadLine, .EnMark)
If you have the brackets in your text file, then you'll need to add extra code to remove them.
I am trying to figure out how to get a message box to show only specific words from a text file, which contains all of the words within the dictionary. I have tried various different ways, but cannot get it to work, but I do think I am on the right track so just need some pointers.
Basically, there is a scrambled up string, which is different every time, and is contained within a label. I want the program to only show words which contains the letters inside the scrambled string, but not sure how to achieve this?
Here is the code that I have so far:
Private Sub btnAnswers_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAnswers.Click
Dim hash As List(Of String) = New List(Of String)(System.IO.File.ReadAllLines("C:\Users\Katie\Documents\Project\dictionary.txt"))
Dim Letters As String
Dim OneCharacter As String
Dim Found As Boolean
Dim item As String
Dim AllCharacters As String
Found = False
Letters = lblLetters.Text
For i = 0 To Letters.Length - 1
OneCharacter = Letters.Substring(i, 1)
For Each item In hash
If item.Contains(OneCharacter) Then
Found = True
AllCharacters = OneCharacter
Else
Found = False
End If
MsgBox(item)
Next
Next i
End Sub
The message box does show up words, from the dictionary, but words can contain letters that are not present in the label string, so my code is wrong. Can anyone help? Apologies, but I am new to programming.
With a simple modification to the previous answer you can restrict the output to only words that contain only the scrambled letters:
Private Sub btnAnswers_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim hash As List(Of String) = New List(Of String)(System.IO.File.ReadAllLines("C:\Users\Katie\Documents\Project\dictionary.txt"))
Dim Letters As String = lblLetters.Text
For Each item As String In hash
Dim word As String = item.ToLower()
For i = 0 To Letters.Length - 1
Dim OneCharacter As Char = Char.ToLower(Letters(i))
While word.Contains(OneCharacter)
word = word.Remove(word.IndexOf(OneCharacter), 1)
End While
Next
If (word.Length = 0) Then
'The given dictionary entry includes all the letters in the label. No more iterations will be performed
MsgBox(item)
Exit For
End If
Next
End Sub
With this code if the scrambled letters contain 'bok' then "book" will get selected. However removing the while loop and leaving only the remove statement, will ensure that only the exact number of each different letter will match. so that 'obok' will be needed to match "book".
As suggested by Steven Doggart, you have to invert the loop nesting. What you want is going through all the dictionary entries and, for each of them, checking if it contains all the letters in the string. Your loop structure is not allowing to do that.
I have performed the required updates in your code. Bear in mind that this code ignores caps ("A" is the same than "a").
Private Sub btnAnswers_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim hash As List(Of String) = New List(Of String)(System.IO.File.ReadAllLines("C:\Users\Katie\Documents\Project\dictionary.txt"))
Dim Letters As String = lblLetters.Text
For Each item As String In hash
Dim Found As Boolean = True
For i = 0 To Letters.Length - 1
Dim OneCharacter As String = Letters.Substring(i, 1)
Dim itemToLower As String = item.ToLower()
If Not itemToLower.Contains(OneCharacter.ToLower()) Then
Found = False
Exit For
End If
Next i
If (Found) Then
'The given dictionary entry includes all the letters in the label. No more iterations will be performed
MsgBox(item)
Exit For
End If
Next
End Sub
This code looks for keys containing all the characters in the given label (not at the contrary), that is: with a label "dict", "dictentry" would be right.
In any case, the whole point of my answer is not delivering a code which you just have to execute; the point of this code is helping you to understand what you did wrong and how to start doing things right. If you are not interested in this exact functionality, you woud have to edit my code such that what you want can be accomplished; or, ideally, you would be writing your own code completely from scratch.
You're calling MsgBox(item) outside of the if statement that determines whether the current word contains the current character. Which means it's going to pop up for every letter, every word. Move MsgBox(item) inside the first half of the if statement if you only want it to show when the letter is actually found in the word.
I'd also suggest following Steven Doggart's advice and reversing the way the loops are nested. If the characters are the outer loop, you could get the message box multiple times per word (e.g., if your letters are "sdf" and one of the words is "foods," it will pop up 3 times).
For Each item In hash
For i = 0 To Letters.Length - 1
OneCharacter = Letters.Substring(i, 1)
If item.Contains(OneCharacter) Then
Found = True
AllCharacters = OneCharacter
MsgBox(item)
Else
Found = False
End If
Next
Next
I'm close to getting this to work, but currently can't get any output to display in the listbox. I had it working, but needed to move some things around to get the join function to work.
In my program, a user enters input into a textbox and an array is displayed in a listbox based on what they type in. For example, if they type in "a", all foods (in the textfile that is connected to the program) that start with "a" will be displayed.
When there is output, I need to find a way to name this array (which is created based on what the user inputs) and join all of the items in the listbox (example: foods stacked on top of each other in the listbox will be shown at the bottom as a string).
I am posting the code that I have thus far; all of the errors that I'm getting (and potentially my logic errors) are just in the first public class until the end of the first if-next statement:
Public Class frmFoods
Dim foods() As String = IO.File.ReadAllLines("foods.txt")
Private Sub btnDisplay_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDisplay.Click
Dim Letter As String = txtLetter.Text.ToUpper
Dim smallerarray() As Array
Dim userarray As String
lstOutput.Items.Clear()
If IsNumeric(txtLetter.Text) = False Then
For Each food As String In foods
smallerarray = listfoods(Letter)
lstOutput.Items.Add(Letter)
userarray = Join(smallerarray, ", ")
lstOutput.Items.Add(userarray)
Next
ElseIf IsNumeric(txtLetter.Text) = True Then
MessageBox.Show("Please enter a letter.")
Else
MessageBox.Show("The text box is empty")
End If
End Sub
Function listfoods(ByVal letter As String) As String()
Dim foodarray(foods.Count - 1) As String
Dim counter As Integer = 0
For Each food As String In foods
If food.StartsWith(letter) Then
foodarray(counter) = food
counter += 1
End If
Next
ReDim Preserve foodarray(counter - 1)
Return foodarray
End Function
you need to save the results of the listfoods function in a dictionary or similar and associate it with a key if you want to 'Name' it, although its not clear why you need to do this
As for listing the foods starting with the particular letter, you just need to iterate your result of the function listfoods and separate each one by a comma don't you?
What you have now will create many lists of each food as you are getting the list of food beginning with a particular letter for each food.. As I understand the question you only need to do that once.
Example:
Private Sub btnDisplay_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDisplay.Click
Dim Letter As String = txtLetter.Text.ToUpper
Dim smallerarray() As Array
Dim userarray As String
lstOutput.Items.Clear()
If IsNumeric(txtLetter.Text) = False Then
'get all items from the file which begin with the letter the user chose
smallerarray = listfoods(Letter)
'add that letter to the output listbox
lstOutput.Items.Add(Letter)
'join all of the elements which begin with that letter
'into a single comma separated string
userarray = Join(smallerarray, ", ")
'add that string to the output
lstOutput.Items.Add(userarray)
ElseIf IsNumeric(txtLetter.Text) = True Then
MessageBox.Show("Please enter a letter.")
Else
MessageBox.Show("The text box is empty")
End If
End Sub
it would probably be useful for you to step through the code and see the values of the variable at each place and compare this with what you expect to see if you can see where the actual value differs from what your logically expect so you can start to identify where the issue is