I needed a function to take a string phrase and scramble it. So I wrote this, but I'm wondering if there is a more efficient/faster way to do it?
Public Function Scramble(phrase As String) As String
Dim rand As New Random()
Dim newPhrase As String = ""
Dim clist As New List(Of String)
' break phrase into characters and add to list
For i As Integer = 1 To Len(phrase)
clist.Add(Mid(phrase.ToLower(), i, 1))
Next
' remove from list randomly and add to new string
Do While clist.Count > 0
Dim r As Integer = rand.Next(0, clist.Count)
newPhrase &= clist(r)
clist.RemoveAt(r)
Loop
Return newPhrase
End Function
Here's Plutonix's one-liner:
Public Function Scramble(ByVal phrase As String) As String
Static rand As New Random()
Return New String(phrase.ToLower.ToCharArray.OrderBy(Function(r) rand.Next).ToArray)
End Function
...and here's an alternate version of your longer form:
Public Function Scramble(ByVal phrase As String) As String
Static rand As New Random()
Dim sb As New System.Text.StringBuilder
Dim chars As New List(Of Char)(phrase.ToLower.ToCharArray)
While chars.Count > 0
Dim r As Integer = rand.Next(0, chars.Count)
sb.Append(chars(r))
chars.RemoveAt(r)
End While
Return sb.ToString
End Function
Related
i have a function getSelectedNumbers that take as input 3 list of number. after a manipulation i need to obtain a string in the format
"[1_3,10,20,30,500],[1_1,2],[]"
if the list is empty i need to have in the string the "[]" char
i wrote the below function but i need to manage the empty case.
Based on comment of Anu6is :
i was able to rewrite my code as below
'''vb
Public Function getSelectedNumbers() As String
Dim selectedNumbers1 As IList(Of Element) = repo.CanvasTerminalProduct.BoardDetails.Panel.pnlSuper3Panel1.Find(".//div[#class='selected']")
Dim selectedNumbers2 As IList(Of Element) = repo.CanvasTerminalProduct.BoardDetails.Panel.pnlSuper3Panel2.Find(".//div[#class='selected']")
Dim selectedNumbers3 As IList(Of Element) = repo.CanvasTerminalProduct.BoardDetails.Panel.pnlSuper3Panel3.Find(".//div[#class='selected']")
Dim list1 As New List(Of String)
Dim list2 As New List(Of String)
Dim list3 As New List(Of String)
For i As Integer = 0 To selectedNumbers1.Count -1
list1.Add(selectedNumbers1(i).GetAttributeValue("innerText").ToString)
Next i
For i As Integer = 0 To selectedNumbers2.Count -1
list2.Add(selectedNumbers2(i).GetAttributeValue("innerText").ToString)
Next i
For i As Integer = 0 To selectedNumbers3.Count -1
list3.Add(selectedNumbers3(i).GetAttributeValue("innerText").ToString)
Next i
'Create List of List
Dim selectedNumbersList As New List(Of List(Of String)) From {list1, list2, list3}
Dim builder As New StringBuilder 'Used to build the output
'Convert all the list in the correct string format using the join
For Each listX As List(Of String) In selectedNumbersList
builder.Append("[1_").Append(String.Join(",", listX)).Append("],") 'String.Join() give you a comma delmited string
Next
'Remove the last, and the [1_] that are not needed
Dim strSelectedNunmber As String = builder.ToString().TrimEnd(","c)
strSelectedNunmber = strSelectedNunmber.ToString().Replace("[1_]","[]")
Return str
End Function
'''
now my question is there is a better way to generate the list1 list2 list3 ?
This is assuming that Element is simply an Integer
Public Function getSelectedNumbers() As String
Dim selectedNumbers1 As New List(Of Integer) From {20, 30, 500, 10, 3} 'Unordered list
Dim selectedNumbers2 As New List(Of Integer) From {1, 2, 500} 'Ordered list
Dim selectedNumbers3 As New List(Of Integer) 'empty list
Dim selectedNumbersList As New List(Of List(Of Integer)) From {selectedNumbers1, selectedNumbers2, selectedNumbers3}
Dim builder As New StringBuilder 'Used to build the output
For Each list In selectedNumbersList
list.Sort() 'Sort your list
builder.Append("[").Append(String.Join(",", list)).Append("],") 'String.Join() give you a comma delmited string
Next
Return builder.ToString.TrimEnd(","c) 'Remove the final comma (,) and return the formatted string
End Function
[3,10,20,30,500],[1,2,500],[]
Does this work for you?
Dim selectedNumbers1 As New List(Of Integer) From {20, 30, 500, 10, 3}
Dim selectedNumbers2 As New List(Of Integer) From {1, 2, 500}
Dim selectedNumbers3 As New List(Of Integer)
'either make 3 loops or 1, but you have to make a list of lists first
Dim selectedNumbersList As New List(Of List(Of Integer)) From {selectedNumbers1, selectedNumbers2, selectedNumbers3}
For Each listX In selectedNumbersList
listX.Sort()
Dim ReturnString As String = "["
If listX.Count > 0 Then
For Each itemvalue In listX
ReturnString &= itemvalue & ","
Next
ReturnString = ReturnString.Remove(ReturnString.Length - 1)
End If
ReturnString &= "]"
Debug.Print(ReturnString)
Next
'[3,10,20,30,500]
'[1,2,500]
'[]
I am successfully converted structure data to string here in plain and (as suggested) in XML serialized way which obviously every has it's own good and bad side effects.
This is sample structure:
Public Structure myList
Dim a As String
Dim b As Integer
Dim c As Double
End Structure
Dim myInstance As New myList
myInstance.a = "Nemo"
myInstance.b = 10
myInstance.c = 3.14
Now I have 2 functions for converting structure data to string:
Dim xString As String = oStructToString(myInstance)
Public Function oStructToString(ByVal obj As Object) As String
Dim structString As String = ""
Dim i As Integer
Dim myType As Type = obj.GetType()
Dim myField As System.Reflection.FieldInfo() = myType.GetFields()
For i = 0 To myField.Length - 1
structString &= myField(i).GetValue(obj)
If i = myField.Length - 1 Then Exit For
structString &= Convert.ToChar(161)
Next i
Return structString
End Function
Dim xString As String = xStructToString(myInstance)
Public Function xStructToString(ByVal obj As Object) As String
Dim x As New Xml.Serialization.XmlSerializer(obj.GetType)
Dim sw As New IO.StringWriter()
x.Serialize(sw, obj)
Return sw.ToString
End Function
But I can't get data back from string to structure.
Public Function oStringToStruct(ByVal xString As String) As Object
So I can call:
Dim mySecondInstance As New myList = oStringToStruct(xString)
Or
Dim mySecondInstance As New myList = xStringToStruct(xString)
How to do that?
So far I came to this:
Public Function xStringToStruct(ByVal xString As String) As Object
Dim x As New Xml.Serialization.XmlSerializer() ''<- what here?
Dim sr As New IO.StringReader(xString)
Return x.Deserialize(sr)
End Function
and this...
By help of har07 still one error remains here...
Public Function oStringToStruct(ByVal xString As String, ByVal type As Type) As Object
Dim structString() As String = xString.Split(Convert.ToChar(161))
Dim myType As Type = type.GetType()
Dim myField As System.Reflection.FieldInfo() = myType.GetFields()
For i As Integer = 0 To structString.Length - 1
myField(i).SetValue(type, structString(i)) ''here crashes
Next i
Return type
End Function
Deserialize xml string back to struct is easier :
Public Function xStringToStruct(ByVal xString As String, ByVal type As Type) As Object
Dim x As New Xml.Serialization.XmlSerializer(type)
Dim sw As New IO.StringReader(xString)
Return x.Deserialize(sw)
End Function
You can use it like so :
Dim xObject As myList = xStringToStruct(xString, GetType(myList))
I am trying to generate a random code in vb.net like this
Dim r As New Random
Response.Write(r.Next())
But I want to generate code with 6 digits and should be alphanumeric like thie A12RV1 and all codes should be like this.
I have tried vb.net random class but I am unable to do that like as I want. I want to get the alphanumeric code each time when I execute the code. How can i achieve this in vb.net?
Try something like this:
Public Function GetRandomString(ByVal iLength As Integer) As String
Dim sResult As String = ""
Dim rdm As New Random()
For i As Integer = 1 To iLength
sResult &= ChrW(rdm.Next(32, 126))
Next
Return sResult
End Function
Or you can do the common random string defining the valid caracters:
Public Function GenerateRandomString(ByRef iLength As Integer) As String
Dim rdm As New Random()
Dim allowChrs() As Char = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLOMNOPQRSTUVWXYZ0123456789".ToCharArray()
Dim sResult As String = ""
For i As Integer = 0 To iLength - 1
sResult += allowChrs(rdm.Next(0, allowChrs.Length))
Next
Return sResult
End Function
I think this will suits your requirement,
Private sub GenerateString()
Dim xCharArray() As Char = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray
Dim xNoArray() As Char = "0123456789".ToCharArray
Dim xGenerator As System.Random = New System.Random()
Dim xStr As String = String.Empty
While xStr.Length < 6
If xGenerator.Next(0, 2) = 0 Then
xStr &= xCharArray(xGenerator.Next(0, xCharArray.Length))
Else
xStr &= xNoArray(xGenerator.Next(0, xNoArray.Length))
End If
End While
MsgBox(xStr)
End Sub
Note: Tested With IDE
EDIT: Modified according to SYSDRAGON's Comment
I need to randomize ALL the lines inside a text file and then save the unsorted lines by replacing the same text file.
How I can do all that?
Dim filepath as String = "text_path"
Dim arr() As String = File.ReadAlllines(filepath)
Dim a As Random
Dim b(str.Length) As Integer
Dim result=1, c As Integer
File.Delete(filepath)
Dim f As StreamWriter = File.AppendText(filepath)
For i = 0 To str.Length
while(result)
result = 0
c = a.Next(0, str.Length)
For j = 0 To b.Length
If b(j) = c Then result = 1
Next
end while
f.WriteLine(arr(c))
Next
f.Close()
Another take on it:
Imports System.IO
Module Module1
Sub CreateFile(destFile As String)
Using sw = New StreamWriter(destFile)
For i = 1 To 200
sw.WriteLine("Line " & i.ToString)
Next
End Using
End Sub
Function RandomList(nNumbers As Integer) As List(Of Integer)
' generate a List of numbers from 0..nNumbers-1 in a random order.
Dim ns As New List(Of Integer)
Dim rnd As New Random
For i = 0 To nNumbers - 1
ns.Insert(rnd.Next(0, i + 1), i)
Next
Return ns
End Function
Sub RandomiseFile(srcFile As String)
Dim lines = File.ReadAllLines(srcFile)
Dim nLines = lines.Count
Dim randomNumbers = RandomList(nLines)
' use a temporary file in case something goes wrong so that
' the original file is still there.
Dim tmpFile = Path.GetTempFileName()
' output the lines in a random order.
Using sw = New StreamWriter(tmpFile)
For i = 0 To nLines - 1
sw.WriteLine(lines(randomNumbers(i)))
Next
End Using
File.Delete(srcFile)
File.Move(tmpFile, srcFile)
End Sub
Sub Main()
Dim fileToUse As String = "C:\temp\makerandom.txt"
CreateFile(fileToUse)
RandomiseFile(fileToUse)
End Sub
End Module
Here is my take on it:
Dim linesList As New List(Of String)(IO.File.ReadAllLines("filepath"))
Dim newLinesList As New List(Of String)
Randomize()
While linesList.Count > 0
Dim randomIndex As Integer = Math.Floor(Rnd() * linesList.Count)
newLinesList.Add(linesList(randomIndex))
linesList.RemoveAt(randomIndex)
End While
IO.File.WriteAllLines("filepath", newLinesList.ToArray)
I need to generate a lot of random 2 character strings for my application. it's a VB console application. basically what I have tried for random strings is this:
Private Function GenerateRandomString(ByVal intLenghtOfString As Integer) As String
'Create a new StrinBuilder that would hold the random string.
Dim randomString As New StringBuilder
'Create a new instance of the class Random
Dim randomNumber As Random = New Random
'Create a variable to hold the generated charater.
Dim appendedChar As Char
'Create a loop that would iterate from 0 to the specified value of intLenghtOfString
For i As Integer = 0 To intLenghtOfString
'Generate the char and assign it to appendedChar
appendedChar = Convert.ToChar(Convert.ToInt32(26 * randomNumber.NextDouble()) + 65)
'Append appendedChar to randomString
randomString.Append(appendedChar)
Next
'Convert randomString to String and return the result.
Return randomString.ToString()
End Function
AND THIS:
Private Function RandomStringGenerator(ByVal intLen As Integer) As String
Dim r As New Random()
Dim i As Integer
Dim strTemp As String = ""
For i = 0 To intLen
strTemp = strTemp & Chr(Int((26 * r.NextDouble()) + 65))
Next
Return r.Next
End Function
But when run, it displays something like this:
SR
SR
SR
SR
SR
SR
SR
SR
SR
SR
BR
BR
BR
BR
BR
BR
BR
KR
KR
KR
KR
and so on.
What is going on? I thought that I used to, a long time ago, be able to just do random.Next.
I've run into similar issues before with the Random object. The problem is that when you instantiate Random it's default seed value is the number of milliseconds since windows started up. And since you are generating random characters at several a millisecond you end up with the same seed number.
Instead you should create a shared random object instead of instantiating a new one on each call.
In another forum I answered a similar question and came up with this generalized function that could be used for your problem. It includes a metric that can be examined to see if there is a bias in the characters being generated.
Dim charUC As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Dim charLC As String = charUC.ToLower
Dim charNUM As String = "0123456789"
Dim charSPEC As String = "``!##$%^&*()-_=+[{]}\|;:',<.>/?" & ControlChars.Quote
Dim charCounts As New Dictionary(Of Char, Integer)
Dim PRNG As New Random 'note - defined at class level
Private Function GetRandChars(ByVal numChars As Integer, _
Optional ByVal includeUpperCase As Boolean = False, _
Optional ByVal includeLowerCase As Boolean = False, _
Optional ByVal includeNumbers As Boolean = False, _
Optional ByVal includeSpecial As Boolean = False) As String
If numChars <= 0 Then Throw New ArgumentException 'must specify valid character count
Dim includeSel As New System.Text.StringBuilder 'contains set of characters
If includeUpperCase Then includeSel.Append(charUC) 'UC to set
If includeLowerCase Then includeSel.Append(charLC) 'LC to set
If includeNumbers Then includeSel.Append(charNUM) 'numbers to set
If includeSpecial Then includeSel.Append(charSPEC) 'specials to set
If includeSel.Length = 0 Then Throw New ArgumentException 'must tell function at least one include
Dim rv As New System.Text.StringBuilder 'return value
'generate specified number of characters
For ct As Integer = 1 To numChars
Dim chSel As Char = includeSel(PRNG.Next(includeSel.Length)) 'select random character
rv.Append(chSel)
'do counts
If charCounts.ContainsKey(chSel) Then
charCounts(chSel) += 1
Else
charCounts.Add(chSel, 1)
End If
Next
Return rv.ToString 'return the random string
End Function