Tutorial [Beginner-Friendly] [VB.NET] String Manipulation Snippets Vault [30 Operations]

Scythe · 04-14-2014, 03:57 PM

So, let's start with a short introduction to what a string is.

In programming, a string is defined as data type that can represent a text, which is consisted from a collection of characters that contains spaces and numerical values as well. Unlike the "Integer" declaration, which can only contain a single numerical value.

Here are different methods of declaring a string:

Code:
'Declare without initializing. 
Dim MyString As String

'Initialize to null. 
Dim MyString As String = Nothing

'Declare with a regular string literal
Dim MyString As String = "Hello, world!"

NOTES:
- The separator after #25 means I'm advancing into the details.
- Dear guests, benefit from the code. Don't ripoff.
- Last thread update: 15/4/2014

1. Replace Function - creates changes in the contents of the string

Code:
	Dim Original As String = "The world is awful"
	Dim Modified As String = Original.Replace("awful", "beautiful")
	MsgBox(Modified)

2. Calculate String Length - calculates how many characters are in the string

Code:
Dim Word As String = "Hello"
        Dim Wordlength As Integer = Word.Length

        MsgBox(Wordlength) 'Output should be 5

3. Reverse String - creates a mirrored text

Code:
Function ReverseString(ByVal value As String) As String

        Dim chr() As Char = value.ToCharArray()
        Array.Reverse(chr)
        Return New String(chr)

    End Function

'Usage:

        Dim MyString As String = "Hello, world"
        Dim ReversedString As String = ReverseString(MyString)
        MsgBox(ReversedString)

4. Construct a String - creates a string from a sequence of characters

Code:
Dim Letters As Char() = {"A"c, "B"c, "C"c, "D"c, "E"c, "F"c, "G"c}
        Dim Alphabet As New String(Letters)

        MsgBox(letters)

5. ToUpper - converts all lowercase characters to uppercase characters

Code:
Dim MyString As String = "hello, world"
        MyString = MyString.ToUpper()
        MsgBox(MyString)

6. ToLower - converts all uppercase characters to lowercase characters

Code:
Dim MyString As String = "HELLO, WORLD"
        MyString = MyString.ToLower()
        MsgBox(MyString)

7. ToSentence - capitalizes first character and every first character after ".", "?", "!"

Code:
Public Function SentenceCase(ByVal MyString() As Char) As String

        Dim sentenceStart As Boolean = True
        Dim I As Integer
        MyString = CStr(MyString).ToLower
        For I = 0 To Len(MyString) - 1
            If sentenceStart Then MyString(I) = CStr(MyString(I)).ToUpper
            If MyString(I) <> " " Then sentenceStart = InStr(".!?", MyString(I))
        Next
        Return MyString

 End Function

'Usage:

        Dim MyString As String = "hello! this is Toxin. how are you?"
        Dim ModifiedString As String = SentenceCase(MyString)
        MsgBox(ModifiedString)

8. ToInverted - creates a mixture of uppercase and lowercase characters

Code:
Private Function ToInverted(ByVal MyString As String) As String

        Dim sResult As String = ""
        Dim sChar As String = ""
        Dim i As Integer
        Dim capital As Boolean = True
        For i = 0 To MyString.Length - 1
            capital = Not capital
            sChar = MyString.Substring(i, 1)
            If capital Then
                sResult &= sChar.ToUpper
            Else
                sResult &= sChar.ToLower
            End If
        Next
        Return sResult

    End Function

'Usage:

        Dim MyString As String = "hello! this is Toxin. how are you?"
        Dim ModifiedString As String = ToInverted(MyString)
        MsgBox(ModifiedString)

9. Split Strings - creates a new line after each word

Code:
Dim MyString As String = "i use sinisterly"
        Dim SplittedString As String() = MyString.Split(New Char() {" "c})
        Dim word As String

        For Each word In SplittedString
            MsgBox(word)
        Next

10. Join Strings - joins splitted strings and creates a sentence

Code:
Dim StringArray(3) As String
        StringArray(0) = "sinisterly"
        StringArray(1) = "is"
        StringArray(2) = "really"
        StringArray(3) = "nice"

        Dim JoinedString As String = String.Join(" ", StringArray)
        MsgBox(JoinedString)

11. Join Strings Without Using String.Join - concatenate strings and creates a sentence

Code:
Dim MyString1 As String = "The forums of Sinisterly "
        Dim MyString2 As String = "are full of joy"
        Dim CompleteString As String

        CompleteString = MyString1 + MyString2
        MsgBox(CompleteString)

12. String.Contains - checks if string contains the specified word

Code:
Dim MyString As String = "hello everyone"
        If MyString.Contains("Hello") Then
            MsgBox("true")
        Else
            MsgBox("false")
        End If

13. String.StartsWith - checks if string starts with the specified word

Code:
Dim MyString As String = "Sinisterly is awesome"

        If MyString.StartsWith("Sinisterly", StringComparison.OrdinalIgnoreCase) Then
            MsgBox("true")
        Else
            MsgBox("false")
        End If

        'NOTE:
        ' "StringComparison.OrdinalIgnoreCase" ignores the character case wether it's upper or lower

14. String.EndsWith - checks if string ends with the specified word

Code:
Dim MyString As String = "Sinisterly is awesome"

        If MyString.EndsWith("awesome", StringComparison.OrdinalIgnoreCase) Then
            MsgBox("true")
        Else
            MsgBox("false")
        End If

        'NOTE:
        ' "StringComparison.OrdinalIgnoreCase" ignores the character case wether it's upper or lower

15. String.Trim - deletes leading and trailing instances of the specified character

Code:
Dim MyString As String = "%%No Percentage%%"
        Dim TrimmedString As String = MyString.Trim("%")

        MsgBox(TrimmedString)

16. String.LTrim - deletes empty spaces (nullspace) at the beginning of the string

Code:
Dim MyString As String = "       hello, world"
        Dim TrimmedString As String = LTrim(MyString)

        MsgBox(TrimmedString)

17. String.RTrim - deletes empty spaces (nullspace) at the end of the string

Code:
Dim MyString As String = "hello, world       "
        Dim TrimmedString As String = RTrim(MyString)

        MsgBox(TrimmedString)

18. Trim Punctuation - deletes punctuation characters, such as "!","?", "*", etc.

Code:
Function TrimPunctuation(ByVal value As String)
        
        '// This function is not written by me (Toxin)
        ' Count leading punctuation.
        Dim removeFromStart As Integer = 0
        For i As Integer = 0 To value.Length - 1 Step 1
            If Char.IsPunctuation(value(i)) Then
                removeFromStart += 1
            Else
                Exit For
            End If
        Next

        ' Count trailing punctuation.
        Dim removeFromEnd As Integer = 0
        For i As Integer = value.Length - 1 To 0 Step -1
            If Char.IsPunctuation(value(i)) Then
                removeFromEnd += 1
            Else
                Exit For
            End If
        Next

        ' Remove leading and trailing punctuation.
        Return value.Substring(removeFromStart,value.Length - removeFromEnd - removeFromStart)

    End Function

'Usage:

        Dim values() As String = {"One?", "--two--", "...three!","four", "five*"}

        For Each value As String In values
            MsgBox(TrimPunctuation(value))
        Next

19. Count Words in String with RegEx - counts how many words are in the string

Code:
Dim MyString As String = "These are four words"
        Dim CoutWords As System.Text.RegularExpressions.MatchCollection = System.Text.RegularExpressions.Regex.Matches(MyString, "[\S]+")

        MessageBox.Show(CoutWords.Count.ToString())

20. Count Chars in String with RegEx - counts how many characters are in the string

Code:
Dim MyString As String = "four"
        Dim CountChars As System.Text.RegularExpressions.MatchCollection = System.Text.RegularExpressions.Regex.Matches(MyString, ".")
        MessageBox.Show(CountChars.Count.ToString())

21. Delimited String - Adds a delimiter in the array of strings

Code:
Dim StringArray As String() = New String(2) {" 1 ", " 2 ", " 3 "}
        Dim ModifiedString As String = String.Join("|", StringArray)
        MsgBox(ModifiedString)

22. Space To Tab - converts spaces to tabs

Code:
Dim MyString As String = "Sinisterly is nice"
        Dim ModifiedString As String = MyString.Replace(" ", vbTab)

        MsgBox(ModifiedString)

23. Tab To Space- converts tabs to spaces

Code:
Dim MyString As String = "Sinisterly" & vbTab & "is" & vbTab & "nice"
        Dim ModifiedString As String = MyString.Replace(vbTab, " ")

        MsgBox(ModifiedString)

24. Space To NewLine - converts spaces to new lines

Code:
Dim MyString As String = "Sinisterly is nice"
        Dim ModifiedString As String = MyString.Replace(" ", ControlChars.Lf)

        MsgBox(ModifiedString)

25. EOL To Space - converts End of Line to sapce

Code:
Dim MyString As String = "Sinisterly" & vbLf & "is" & vbLf & "nice"
        Dim ModifiedString As String = MyString.Replace(ControlChars.Lf, " ")

        MsgBox(ModifiedString)

26. ASCII To HEX - converts normal text to Hex

Code:
Dim MyString As String = "Sinisterly is nice".ToCharArray
            Dim HexString As String
            Dim sHex As String = ""
            For Each ch As Char In MyString
                sHex += Convert.ToString(Convert.ToInt32(ch), 16) & " "
            Next
            HexString = sHex
            MsgBox(HexString)

27. HEX To ASCII - converts Hex to normal text

Code:
Dim MyHexString As String = "53 69 6e 69 73 74 65 72 6c 79 20 69 73 20 6e 69 63 65"
        Dim MyASCIIString As String
        Dim arrStrings As String() = MyHexString.Trim(" "c).Split(" "c)
        Dim sText As String = ""
        For Each st As String In arrStrings
            sText += Convert.ToChar(Convert.ToInt32(st, 16))
        Next
        MyASCIIString = sText
        MsgBox(MyASCIIString)

28. ASCII To Base64 - converts normal text to Base64

Code:
Dim MyString As String = "Sinisterly is nice"
        Dim Base64String As String
        Dim [Byte] As Byte() = System.Text.Encoding.UTF8.GetBytes(MyString)

        Base64String = Convert.ToBase64String([Byte])
        MsgBox(Base64String)

29. Base64 To ASCII - converts Base64 to normal text

Code:
Dim MyBase64String As String = "U2luaXN0ZXJseSBpcyBuaWNl"
        Dim MyASCIIString As String
        Dim [Byte] As Byte() = Convert.FromBase64String(MyBase64String)

        MyASCIIString = System.Text.Encoding.UTF8.GetString([Byte])
        MsgBox(MyASCIIString)

30. ASCII To ROT13 and Vice Versa - encrypts to/or decrypts from ROT13

Code:
'/ENC
 Dim MyString As String = "Hello, world"
        Dim EncOrDec As New StringBuilder
        Dim CheckCharIndex As Integer
        Dim CharIndex As Integer

        For Each xChr As Char In MyString

            If (Not Char.IsLetter(xChr)) Then
                EncOrDec.Append(xChr)
                Continue For
            End If

            CheckCharIndex = Asc("a") - (Char.IsUpper(xChr) * -32)
            CharIndex = ((Asc(xChr) - CheckCharIndex) + 13) Mod 26

            EncOrDec.Append(Chr(CharIndex + CheckCharIndex))
        Next
        MsgBox(EncOrDec.ToString())

'/DEC
  Dim MyString As String = "Uryyb, jbeyq"
        Dim EncOrDec As New StringBuilder
        Dim CheckCharIndex As Integer
        Dim CharIndex As Integer

        For Each xChr As Char In MyString

            If (Not Char.IsLetter(xChr)) Then
                EncOrDec.Append(xChr)
                Continue For
            End If

            CheckCharIndex = Asc("a") - (Char.IsUpper(xChr) * -32)
            CharIndex = ((Asc(xChr) - CheckCharIndex) + 13) Mod 26

            EncOrDec.Append(Chr(CharIndex + CheckCharIndex))
        Next
        MsgBox(EncOrDec.ToString())

xornull · 04-14-2014, 04:08 PM

I will have a final exam in school and it will contain this, thank you.

Even though I hate C# Biggrin

.

Scythe · 04-14-2014, 04:16 PM

@xornull The snippets I wrote covers the basics of string manipulation. Soon, I will dive deeper into the details and post more advanced functions. I just need a little rest since I have been working those snippets for 2 hours.

A C# version will be also posted for those who hate VB Tongue

Enjoy!

Curse · 04-15-2014, 12:54 PM

Looks like a really nice Tutorial. Teaches the quite basic way of mani on Strings.

Great work.

Scythe · 04-15-2014, 10:31 PM

@Curse, thanks - really appreciated
If you, or any other user need help, I'm always available to explain and assist! Smile

Curse · 04-15-2014, 11:05 PM

(04-15-2014, 10:31 PM)Scythe Wrote: @Curse, thanks - really appreciated
If you, or any other user need help, I'm always available to explain and assist!

No worries, I am all about VB.Net coding, so I don't think I would really need your help.
But, if I am stuck somewhere, I would contact you.
You can PM me however, if you want that. Tongue

Reiko · 04-17-2014, 02:22 AM

"ROT13 encryption". Everything you said, even if it was 100% correct, is now invalid. You're dumb. Go away.

Oni · 04-17-2014, 02:24 AM

(04-17-2014, 02:22 AM)Starfall Wrote: "ROT13 encryption". Everything you said, even if it was 100% correct, is now invalid. You're dumb. Go away.

Lbh ner orvat irel ehqr gbqnl.

Scythe · 04-17-2014, 10:01 AM

(04-17-2014, 02:22 AM)Starfall Wrote: "ROT13 encryption". Everything you said, even if it was 100% correct, is now invalid. You're dumb. Go away.

The code was rotating "a", "b", "g", "o", "n", "l", "v" correctly but it was still bugged. I don't see the reason of calling me dumb. Mistakes happen. If you want, I would like to start a programming challenge with you on the 10th of June to show you how dumb I am.

Regarding @Oni's reply, this should make sense now

Code:
Dim MyString As String = "Lbh ner orvat irel ehqr gbqnl."
        Dim EncOrDec As New StringBuilder
        Dim CheckCharIndex As Integer
        Dim CharIndex As Integer

        For Each xChr As Char In MyString

            If (Not Char.IsLetter(xChr)) Then
                EncOrDec.Append(xChr)
                Continue For
            End If

            CheckCharIndex = Asc("a") - (Char.IsUpper(xChr) * -32)
            CharIndex = ((Asc(xChr) - CheckCharIndex) + 13) Mod 26

            EncOrDec.Append(Chr(CharIndex + CheckCharIndex))
        Next
        MsgBox(EncOrDec.ToString())

Tmarmol · 02-11-2015, 10:25 AM

Very useful bro!!
I appreciate so much your post