I'm making a program which a user enters an item in a text box and the program will check if the item is in the string. Here is my current code:
Try
Dim Request As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create("https://www.dropbox.com/s/2l37j6v0ofsenus/Foods.txt?dl=1")
Dim Response As System.Net.HttpWebResponse = Request.GetResponse()
Dim sr As System.IO.StreamReader = New System.IO.StreamReader(Response.GetResponseStream)
Dim Foods As String = sr.ReadToEnd()
If Foods.Contains(TXTItem1.Text) Then
Dim Substring As String = Foods.Split(TXTItem1.Text)(1)
Dim SubString1 As String = Substring.Split("-")(1)
Dim SPValue As String = SubString1.Split(vbNewLine)(0)
MsgBox("That item is worth " + SPValue + " SmartPoints!", info)
Else
MsgBox("Item is not found in our list!", critical)
End If
Catch ex As Exception
MsgBox("Error")
End Try
I want to make it where when it checks the string, it is not case sensitive. So if a user enters "eggs" and the string contains "Eggs", it will do the function still even tho its lower-case. How can I do this? Thanks!
If you convert the string you're testing to lowercase, and also the string you are testing against to lowercase, then case is no longer a consideration!
There are functions that can do this for you, but the logic behind them is always the same ... Caseless comparison requires both pieces of data to be converted to either all lowercase (or all uppercase), before the comparison is undertaken. I
The linked question that's referred to by #jacob-h in the comment above already has answers to your question, but I prefer an extension method in this case.
Here's an extension method version that I've been using for a while. Add a new Module to your project (or use an existing one if you find it appropriate), and add this extension method to it:
<Runtime.CompilerServices.Extension>
Public Function ContainsIgnoreCase(ByVal s As String, ByVal value As String)
Return s.IndexOf(value, StringComparison.OrdinalIgnoreCase) >= 0
End Function
Then you can use something like this:
If Foods.ContainsIgnoreCase(TXTItem1.Text) Then
' Do your thing.
End If
Related
I was chastised by a professional developer with a lot of years of experience for Hard Coding my DB name
OK I get it we sometimes carry our bad codding habits with us till we learn the correct way to code
I have finally learned to use Interpolated Strings (personal view they are not pretty)
My Question involves the two Sub's posted below GetDB runs first then HowMany is called from GetDB
Sorry for stating the obvious my reason is I think that NewWord.db gets declared in GetDB and works in HowMany without the same construction Just a Wild Guess
Notice NO $ or quotation used in HowMany
Both Sub's produce desired results
The question is Why don't both statements need to be constructed the same?
Public Sub HowMany()
'Dim dbName As String = "NewWord.db"
Dim conn As New SQLiteConnection("Data Source ='{NewWord.db}';Version=3;")
tot = dgvOne.RowCount ' - 1
tbMessage.Text = "DGV has " & tot.ToString & " Rows"
End Sub
Private Sub GetDB()
Dim str2 As String
Dim s1 As Integer
'Dim dbName As String = "NewWord.db"
Using conn As New SQLiteConnection($"Data Source = '{"NewWord.db"}' ;Version=3;")
conn.Open()
That second method is a ridiculous and pointless use of string interpolation. What could possibly be the point of inserting a literal String into a literal String? The whole point is that you can insert values determined at run time. That second code is equivalent to using:
"Data Source = '" & "NewWord.db" & "' ;Version=3;"
What's the point of that? The idea is that you retrieve your database name from somewhere at run time, e.g. your config file, and then insert that into the template String, e.g.
Dim dbName = GetDbNameFromExternalFile()
Using conn As New SQLiteConnection($"Data Source = '{dbName}' ;Version=3;")
Now the user can edit that external file to change the database name after deploying the application. How could they change the name in your code?
To be clear, string interpolation is just native language support for the String.Format method. You can see that if you make a mistake that generates an exception and the that exception will refer to the String.Format method. In turn, String.Format is a way to make code that multiple values into a long template easier to read than if multiple concatenation operators were used.
Having lots of quotes and ampersands makes code hard to read and error-prone. I've lost count of the number of times people miss a single quote or a space or the like in a String because they couldn't read there messy code. Personally, I'll rarely use two concatenation operators in the same expression and never three. I'll do this:
Dim str = "some text" & someVar
but I'll rarely do this:
Dim str = "some text" & someVar & "some more text"
and I'll never do this:
Dim str = "some text" & someVar & "some more text" & someOtherVar
Before string interpolation, I would use String.Format:
Dim str = String.Format("some text{0}some more text{1}", someVar, someOtherVar)
Nowadays, I'll generally use string interpolation:
Dim str = $"some text{someVar}some more text{someOtherVar}"
Where I may still use String.Format over string interpolation is if one value is getting inserted in multiple places and/or where the text template and/or the expressions are long so that I can break the whole thing over multiple lines, e.g.
Dim str = String.Format("some text{0}some more text{1}yet more text{0}",
someVar,
someOtherVar)
I have no idea what NewWord.db is so I made a class to represent it.
Public Class NewWord
Public Shared Property db As String = "The db Name"
End Class
HowMany is not a very good name for your sub. Try to use more descriptive names.
The first sub doesn't even use the connection. The connection string in that code is a literal string. It will not consider NewWord.db as a variable. You will not notice this because you never attempt to open the connection. In my version you check the connection string with a Debug.Print.
I changed the last line to use and interpolated string. It is not necessary to call .ToString on tot.
Private Sub DisplayGridCount()
Dim conn As New SQLiteConnection("Data Source ='{NewWord.db}';Version=3;")
Debug.Print(conn.ConnectionString)
Dim tot = DataGridView1.RowCount
TextBox1.Text = $"DGV has {tot} Rows"
End Sub
The second snippet starts off with 2 unused variables. I deleted them. Again, the Debug.Print to show the difference in the 2 strings.
Private Sub TestConnection()
Using conn As New SQLiteConnection($"Data Source = '{NewWord.db}' ;Version=3;")
Debug.Print(conn.ConnectionString)
'conn.Open()
End Using
End Sub
As to where to store connection strings see https://learn.microsoft.com/en-us/dotnet/framework/data/adonet/protecting-connection-information and Where to store Connection String
I have saved written a text file and it currently reads:
"first","surname","pass"
I want to read the password column so the 3rd one and define that as a variable. Its basically for a login, if pass in text file matches the entered pass (from user).
I have searched for about an hour now and no luck. Could someone guide me to a correct path.
Thanks.
Simple example of reading a small file line by line and splitting each one into fields:
' get the values from the user somehow:
Dim first As String = "James"
Dim surname As String = "Bond"
Dim pass As String = "007"
Dim validated As Boolean = False ' assume wrong until proven otherwise
' check the file:
Dim fileName As String = "c:\some folder\path\somefile.txt"
Dim lines As New List(Of String)(System.IO.File.ReadAllLines(fileName))
For Each line As String In lines
Dim values() As String = line.Split(",")
If values.Length = 3 Then
If values(0).Trim(Chr(34)) = first AndAlso
values(1).Trim(Chr(34)) = surname AndAlso
values(2).Trim(Chr(34)) = pass Then
validated = True
Exit For
End If
End If
Next
' check the result
If validated Then
MessageBox.Show("Login Successful!")
Else
MessageBox.Show("Login Failed!")
End If
If this is a CSV file, as seems to be the case, then the easiest way to read it will be with the TextFieldParser class. The MSDN already provides an excellent example for how to use it to read a CSV file, so I won't bother reproducing it here.
I'm trying to delete a selected row, then save the rest into a file. However, when I save it, it totally empties the file.
Console.Write("Please eneter the first name of the student you wish to search for: ")
searchfname = Console.ReadLine
searchfname = StrConv(searchfname, VbStrConv.ProperCase)
Console.Write("Please enter the second name of the student you wish to search for: ")
searchsname = Console.ReadLine
searchsname = StrConv(searchsname, VbStrConv.ProperCase)
Dim foundItem() As String = Nothing
Dim foundline As String = Nothing
Dim fnsearch As String = String.Join(searchfname, searchsname)
Dim lines As New List(Of String)(File.ReadAllLines("F:\Computing\Spelling Bee\stdnt&staffdtls.csv"))
For Each line As String In lines
If searchfname = item(3) And searchsname = item(4) Then
Console.WriteLine(line)
Console.WriteLine()
Console.WriteLine("Are you sure you wish to delete this record? (y/n)")
End If
Dim answer As String
answer = Console.ReadLine
If answer = "y" Or answer = "Y" Then
Console.Clear()
lines.Remove(line)
Using sw As New StreamWriter("F:\Computing\Spelling Bee\stdnt&staffdtls.csv")
sw.WriteLine(lines.ToString)
End Using
ElseIf answer = "n" Or answer = "N" Then
staffmenu()
End If
Next
Look at this line in your code:
sw.WriteLine(lines.ToString)
Extract the lines.ToString expression from that statement. The result of that expression is "System.String". You are telling your stream writer to write the text "System.String" to the file.
To fix it, you need something more like this:
Using sw As New StreamWriter("F:\Computing\Spelling Bee\stdnt&staffdtls.csv")
For Each line As String In lines
sw.WriteLine(line)
Next line
End Using
The method List(Of T).ToString does not produce a value that includes the elements of the collection. Instead it will just return the type name.
The API you are looking for is File.WriteAllLines. Using this instead of StreamWriter and the Using block
File.WriteAllLines("F:\Computing\Spelling Bee\stdnt&staffdtls.csv", lines)
I can see that this issue can be resolved from the given answers and comment, but I would like to add an alternative to use Join function in writing to a file. Try like this may be of help:
Using sw As New StreamWriter(.....)
sw.WriteLine(Join(lines.ToArray(), Environment.NewLine))
End Using
Since using VB.Net, this is a vb.net specific solution can not be used in C#. For C#, use string.join instead.
Hope it helps too!
Does anybody know how to lowercase the first word for each line in a textbox?
Not the first letter, the first word.
I tried like this but it doesn't work:
For Each iz As String In txtCode.Text.Substring(0, txtCode.Text.IndexOf(" "))
iz = LCase(iz)
Next
When you call Substring, it is making a copy of that portion of the string and returning it as a new string object. So, even if you were successfully changing the value of that returned sub-string, it still would not change the original string in the Text property.
However, strings in .NET are immutable reference-types, so when you set iz = ... all you are doing is re-assigning the iz variable to point to yet another new string object. When you set iz, you aren't even touching the value of that copied sub-string to which it previously pointed.
In order to change the value of the text box, you must actually assign a new string value to its Text property, like this:
txtCode.Text = "the new value"
Since that is the case, I would recommend building a new string, using a StringBuilder object, and then, once the modified string is complete, then set the text box's Text property to that new string, for instance:
Dim builder As New StringBuilder()
For Each line As String In txtCode.Text.Split({Environment.NewLine}, StringSplitOptions.None)
' Fix case and append line to builder
Next
txtCode.Text = builder.ToString()
The solutions here are interesting but they are ignoring a fundamental tool of .NET: regular expressions. The solution can be written in one expression:
Dim result = Regex.Replace(txtCode.Text, "^\w+",
Function (match) match.Value.ToLower(), RegexOptions.Multiline)
(This requires the import System.Text.RegularExpressions.)
This solution is likely more efficient than all the other solutions here (It’s definitely more efficient than most), and it’s less code, thus less chance of a bug and easier to understand and to maintain.
The problem with your code is that you are running the loop only on each character of the first word in the whole TextBox text.
This code is looping over each line and takes the first word:
For Each line As String In txtCode.Text.Split(Environment.NewLine)
line = line.Trim().ToLower()
If line.IndexOf(" ") > 0 Then
line = line.Substring(0, line.IndexOf(" ")).Trim()
End If
// do something with 'line' here
Next
Loop through each of the lines of the textbox, splitting all of the words in the line, making sure to .ToLower() the first word:
Dim strResults As String = String.Empty
For Each strLine As String In IO.File.ReadAllText("C:\Test\StackFlow.txt").Split(ControlChars.NewLine)
Dim lstWords As List(Of String) = strLine.Split(" ").ToList()
If Not lstWords Is Nothing Then
strResults += lstWords(0).ToLower()
If lstWords.Count > 1 Then
For intCursor As Integer = 1 To (lstWords.Count - 1)
strResults += " " & lstWords(intCursor)
Next
End If
End If
Next
I used your ideas guys and i made it up to it like this:
For Each line As String In txtCode.Text.Split(Environment.NewLine)
Dim abc() As String = line.Split(" ")
txtCode.Text = txtCode.Text.Replace(abc(0), LCase(abc(0)))
Next
It works like this. Thank you all.
i am trying to split a string up into separate lines with the following code, but for some reason it is also removing the spaces in the string.
Dim calculationText As String
calculationText = File.ReadAllText(fileName)
Dim fields() As String
fields = calculationText.Split(vbCrLf)
when i am in debugger mode, i look at fields, and every element has a line of the string but all the spaces and tabs are removed.
any reason for this?
If you are reading from a file, can you use:
Sub Main()
Dim fields As New List(Of String)
' read file into list
Using sr As System.IO.StreamReader = My.Computer.FileSystem.OpenTextFileReader(filename)
Try
Do While sr.Peek() >= 0
fields.Add(sr.ReadLine())
Loop
Finally
If sr IsNot Nothing Then sr.Close()
End Try
End Using
' check results
For Each line As String In fields
Console.WriteLine(line)
Next
End Sub
How 'bout:
Dim fields() As String = File.ReadAllLines(fileName)
As for why string.Split() is doing weird things...
vbCrLf is a string, and there's not an overload for string.split that accepts a single string parameter. If he were to turn on Option Explicit it wouldn't even compile, but since it's off, vbCrLf can be interpreted as an array of characters. And in this code, that's exactly what happens:
Sub Main()
Dim z As String = "The quick brown" & vbCrLf & " fox jumps over the lazy dogs."
Dim a() As String = z.Split(vbCrLf)
For Each c As String In a
Console.WriteLine(c)
Next
Console.ReadKey(True)
End Sub
You'll see two line breaks between the 1st and 2nd parts of that string. Something else is stripping out the spaces. Can you share the larger code block?
Gotta say I've never seen it do that, and I've used String.Split extensively. Are they really really gone, or is it a trick of the debugger?
There's not actually any .Split method that takes one string as the parameter, so the VB compiler would be doing "things" behind the scenes to pick a different overload. To try and force the correct overload, you could try calculationText.Split(vbCrLf.ToCharArray()). I doubt it will help, but you never know :-)