Right Function

Returns a String containing a specified number of characters from the right side of a string.

Syntax

Right(string, length)

Parameters

• string - Required. String expression from which the rightmost characters are returned.
• length - Required. Long indicating how many characters to return. If 0, a zero-length string ("") is returned. If greater than or equal to the number of characters in string, the entire string is returned.

Return Value

Returns a String containing the specified number of characters from the right side of the string.

Remarks

The Right function extracts a substring from the end of a string. It is commonly used for: - Extracting file extensions - Getting the last N characters of a string - Parsing fixed-width data from the right - Removing prefixes or extracting suffixes

Important Notes: - If length is 0, an empty string ("") is returned - If length >= Len(string), the entire string is returned - If string is Null, Right returns Null - If length is negative, a runtime error occurs (Error 5: Invalid procedure call or argument) - The function is 1-based (counts from position 1, not 0)

Behavior with Different Length Values:

Typical Uses

1. File Extensions: Extract file extension from filename
2. Data Parsing: Extract rightmost fields from fixed-width data
3. String Validation: Check string endings/suffixes
4. Number Formatting: Get last digits of numbers
5. Path Manipulation: Extract filename from path
6. Text Processing: Remove prefixes, keep suffixes
7. Data Extraction: Get trailing characters from codes/IDs
8. String Truncation: Keep only the rightmost portion

Basic Examples

Example 1: Extract File Extension

Dim filename As String
Dim extension As String

filename = "document.txt"
extension = Right(filename, 4)  ' Returns ".txt"

Example 2: Get Last N Characters

Dim accountNumber As String
Dim lastFour As String

accountNumber = "1234567890"
lastFour = Right(accountNumber, 4)  ' Returns "7890"

Example 3: Check String Ending

Dim filename As String

filename = "report.pdf"
If Right(filename, 4) = ".pdf" Then
MsgBox "This is a PDF file"
End If

Example 4: Extract from Fixed-Width Data

Dim record As String
Dim zipCode As String

record = "John Doe          New York     10001"
zipCode = Right(record, 5)  ' Returns "10001"

Common Patterns

Pattern 1: GetFileExtension

Function GetFileExtension(filename As String) As String
' Extract file extension including the dot
Dim dotPos As Integer

dotPos = InStrRev(filename, ".")

If dotPos > 0 Then
GetFileExtension = Right(filename, Len(filename) - dotPos + 1)
Else
GetFileExtension = ""
End If
End Function

Pattern 2: GetLastNChars

Function GetLastNChars(text As String, n As Long) As String
' Safely get last N characters (won't error if string is too short)
If n <= 0 Then
GetLastNChars = ""
ElseIf n >= Len(text) Then
GetLastNChars = text
Else
GetLastNChars = Right(text, n)
End If
End Function

Pattern 3: EndsWithString

Function EndsWithString(text As String, suffix As String, _
Optional caseSensitive As Boolean = True) As Boolean
' Check if string ends with a specific suffix
Dim textEnd As String
Dim suffixLen As Long

suffixLen = Len(suffix)

If suffixLen > Len(text) Then
EndsWithString = False
Exit Function
End If

textEnd = Right(text, suffixLen)

If caseSensitive Then
EndsWithString = (textEnd = suffix)
Else
EndsWithString = (UCase(textEnd) = UCase(suffix))
End If
End Function

Pattern 4: RemovePrefix

Function RemovePrefix(text As String, prefixLen As Long) As String
' Remove prefix by keeping rightmost characters
If prefixLen >= Len(text) Then
RemovePrefix = ""
Else
RemovePrefix = Right(text, Len(text) - prefixLen)
End If
End Function

Pattern 5: PadLeftToLength

Function PadLeftToLength(text As String, totalLength As Long, _
Optional padChar As String = " ") As String
' Pad string on the left to reach desired length
Dim currentLen As Long
Dim padding As String

currentLen = Len(text)

If currentLen >= totalLength Then
PadLeftToLength = Right(text, totalLength)
Else
padding = String(totalLength - currentLen, padChar)
PadLeftToLength = padding & text
End If
End Function

Pattern 6: GetFilenameFromPath

Function GetFilenameFromPath(fullPath As String) As String
' Extract filename from full path
Dim slashPos As Integer

slashPos = InStrRev(fullPath, "\")

If slashPos > 0 Then
GetFilenameFromPath = Right(fullPath, Len(fullPath) - slashPos)
Else
GetFilenameFromPath = fullPath
End If
End Function

Pattern 7: TruncateLeft

Function TruncateLeft(text As String, maxLength As Long, _
Optional ellipsis As String = "...") As String
' Truncate from left, keeping rightmost characters
Dim textLen As Long

textLen = Len(text)

If textLen <= maxLength Then
TruncateLeft = text
Else
TruncateLeft = ellipsis & Right(text, maxLength - Len(ellipsis))
End If
End Function

Pattern 8: FormatAccountNumber

Function FormatAccountNumber(accountNum As String) As String
' Format account number showing only last 4 digits
Dim lastFour As String

If Len(accountNum) > 4 Then
lastFour = Right(accountNum, 4)
FormatAccountNumber = "****" & lastFour
Else
FormatAccountNumber = accountNum
End If
End Function

Pattern 9: ExtractDomainExtension

Function ExtractDomainExtension(url As String) As String
' Extract domain extension (.com, .org, etc.)
Dim dotPos As Integer

' Find last dot
dotPos = InStrRev(url, ".")

If dotPos > 0 Then
ExtractDomainExtension = Right(url, Len(url) - dotPos + 1)
Else
ExtractDomainExtension = ""
End If
End Function

Pattern 10: GetTrailingDigits

Function GetTrailingDigits(text As String) As String
' Extract trailing numeric characters
Dim i As Integer
Dim digitCount As Integer

digitCount = 0

For i = Len(text) To 1 Step -1
If IsNumeric(Mid(text, i, 1)) Then
digitCount = digitCount + 1
Else
Exit For
End If
Next i

If digitCount > 0 Then
GetTrailingDigits = Right(text, digitCount)
Else
GetTrailingDigits = ""
End If
End Function

Advanced Usage

Example 1: File Extension Validator

' Comprehensive file extension validation and management
Class FileExtensionValidator
Private m_validExtensions As Collection

Public Sub Initialize()
Set m_validExtensions = New Collection
End Sub

Public Sub AddValidExtension(extension As String)
Dim ext As String

' Normalize extension (add dot if missing)
If Left(extension, 1) <> "." Then
ext = "." & extension
Else
ext = extension
End If

On Error Resume Next
m_validExtensions.Add ext, UCase(ext)
On Error GoTo 0
End Sub

Public Function IsValidFile(filename As String) As Boolean
Dim ext As String
Dim dotPos As Integer

dotPos = InStrRev(filename, ".")

If dotPos = 0 Then
IsValidFile = False
Exit Function
End If

ext = Right(filename, Len(filename) - dotPos + 1)

On Error Resume Next
Dim temp As String
temp = m_validExtensions(UCase(ext))
IsValidFile = (Err.Number = 0)
On Error GoTo 0
End Function

Public Function GetExtension(filename As String) As String
Dim dotPos As Integer

dotPos = InStrRev(filename, ".")

If dotPos > 0 Then
GetExtension = Right(filename, Len(filename) - dotPos + 1)
Else
GetExtension = ""
End If
End Function

Public Function ChangeExtension(filename As String, newExt As String) As String
Dim dotPos As Integer
Dim baseName As String
Dim ext As String

dotPos = InStrRev(filename, ".")

If dotPos > 0 Then
baseName = Left(filename, dotPos - 1)
Else
baseName = filename
End If

' Normalize new extension
If Left(newExt, 1) <> "." Then
ext = "." & newExt
Else
ext = newExt
End If

ChangeExtension = baseName & ext
End Function

Public Function GetValidExtensions() As String
Dim ext As Variant
Dim result As String

result = ""

For Each ext In m_validExtensions
If result <> "" Then result = result & ", "
result = result & ext
Next ext

GetValidExtensions = result
End Function
End Class

Example 2: Path Parser Module

' Parse and manipulate file paths
Module PathParser
Public Function GetFilename(fullPath As String) As String
' Extract filename from full path
Dim slashPos As Integer

slashPos = InStrRev(fullPath, "\")

If slashPos > 0 Then
GetFilename = Right(fullPath, Len(fullPath) - slashPos)
Else
GetFilename = fullPath
End If
End Function

Public Function GetDirectory(fullPath As String) As String
' Extract directory from full path
Dim slashPos As Integer

slashPos = InStrRev(fullPath, "\")

If slashPos > 0 Then
GetDirectory = Left(fullPath, slashPos - 1)
Else
GetDirectory = ""
End If
End Function

Public Function GetFilenameWithoutExtension(fullPath As String) As String
' Get filename without extension
Dim filename As String
Dim dotPos As Integer

filename = GetFilename(fullPath)
dotPos = InStrRev(filename, ".")

If dotPos > 0 Then
GetFilenameWithoutExtension = Left(filename, dotPos - 1)
Else
GetFilenameWithoutExtension = filename
End If
End Function

Public Function GetExtension(fullPath As String) As String
' Get file extension including dot
Dim filename As String
Dim dotPos As Integer

filename = GetFilename(fullPath)
dotPos = InStrRev(filename, ".")

If dotPos > 0 Then
GetExtension = Right(filename, Len(filename) - dotPos + 1)
Else
GetExtension = ""
End If
End Function

Public Function CombinePath(directory As String, filename As String) As String
' Combine directory and filename
If Right(directory, 1) = "\" Then
CombinePath = directory & filename
Else
CombinePath = directory & "\" & filename
End If
End Function

Public Function GetParentDirectory(fullPath As String) As String
' Get parent directory
Dim dir As String
Dim slashPos As Integer

dir = GetDirectory(fullPath)
slashPos = InStrRev(dir, "\")

If slashPos > 0 Then
GetParentDirectory = Left(dir, slashPos - 1)
Else
GetParentDirectory = ""
End If
End Function
End Module

Example 3: String Suffix Matcher

' Match and validate string suffixes
Class StringSuffixMatcher
Private m_caseSensitive As Boolean

Public Sub Initialize(Optional caseSensitive As Boolean = True)
m_caseSensitive = caseSensitive
End Sub

Public Function EndsWith(text As String, suffix As String) As Boolean
' Check if string ends with suffix
Dim textEnd As String
Dim suffixLen As Long

suffixLen = Len(suffix)

If suffixLen > Len(text) Then
EndsWith = False
Exit Function
End If

textEnd = Right(text, suffixLen)

If m_caseSensitive Then
EndsWith = (textEnd = suffix)
Else
EndsWith = (UCase(textEnd) = UCase(suffix))
End If
End Function

Public Function EndsWithAny(text As String, suffixes() As String) As Boolean
' Check if string ends with any of the provided suffixes
Dim i As Integer

For i = LBound(suffixes) To UBound(suffixes)
If EndsWith(text, suffixes(i)) Then
EndsWithAny = True
Exit Function
End If
Next i

EndsWithAny = False
End Function

Public Function RemoveSuffix(text As String, suffix As String) As String
' Remove suffix if present
If EndsWith(text, suffix) Then
RemoveSuffix = Left(text, Len(text) - Len(suffix))
Else
RemoveSuffix = text
End If
End Function

Public Function GetMatchingSuffix(text As String, suffixes() As String) As String
' Return the matching suffix, or empty string
Dim i As Integer

For i = LBound(suffixes) To UBound(suffixes)
If EndsWith(text, suffixes(i)) Then
GetMatchingSuffix = suffixes(i)
Exit Function
End If
Next i

GetMatchingSuffix = ""
End Function

Public Function ReplaceSuffix(text As String, oldSuffix As String, _
newSuffix As String) As String
' Replace suffix if present
If EndsWith(text, oldSuffix) Then
ReplaceSuffix = Left(text, Len(text) - Len(oldSuffix)) & newSuffix
Else
ReplaceSuffix = text
End If
End Function
End Class

Example 4: Account Number Formatter

' Format and mask account numbers securely
Class AccountNumberFormatter
Private m_maskChar As String
Private m_visibleDigits As Integer

Public Sub Initialize(Optional maskChar As String = "*", _
Optional visibleDigits As Integer = 4)
m_maskChar = maskChar
m_visibleDigits = visibleDigits
End Sub

Public Function FormatAccountNumber(accountNum As String) As String
' Format account number showing only last N digits
Dim lastDigits As String
Dim maskedLength As Integer

If Len(accountNum) <= m_visibleDigits Then
FormatAccountNumber = accountNum
Exit Function
End If

lastDigits = Right(accountNum, m_visibleDigits)
maskedLength = Len(accountNum) - m_visibleDigits

FormatAccountNumber = String(maskedLength, m_maskChar) & lastDigits
End Function

Public Function FormatWithSpaces(accountNum As String, _
Optional groupSize As Integer = 4) As String
' Format with spaces every N characters
Dim formatted As String
Dim i As Integer
Dim maskedNum As String

maskedNum = FormatAccountNumber(accountNum)
formatted = ""

For i = 1 To Len(maskedNum) Step groupSize
If i > 1 Then formatted = formatted & " "
formatted = formatted & Mid(maskedNum, i, groupSize)
Next i

FormatWithSpaces = formatted
End Function

Public Function GetLastDigits(accountNum As String) As String
' Get only the visible digits
If Len(accountNum) <= m_visibleDigits Then
GetLastDigits = accountNum
Else
GetLastDigits = Right(accountNum, m_visibleDigits)
End If
End Function

Public Function ValidateAccountNumber(accountNum As String, _
minLength As Integer, _
maxLength As Integer) As Boolean
' Validate account number length
Dim numLen As Integer

numLen = Len(accountNum)
ValidateAccountNumber = (numLen >= minLength And numLen <= maxLength)
End Function

Public Sub SetMaskChar(maskChar As String)
m_maskChar = maskChar
End Sub

Public Sub SetVisibleDigits(visibleDigits As Integer)
m_visibleDigits = visibleDigits
End Sub
End Class

Error Handling

The Right function generates runtime errors in specific situations:

Error 5: Invalid procedure call or argument - Occurs when length parameter is negative

Error 94: Invalid use of Null - Occurs when string parameter is Null

Example error handling:

On Error Resume Next
result = Right(userInput, charCount)
If Err.Number <> 0 Then
MsgBox "Error extracting characters: " & Err.Description
result = ""
End If
On Error GoTo 0

Best practice for safe usage:

Function SafeRight(text As String, length As Long) As String
If IsNull(text) Then
SafeRight = ""
Exit Function
End If

If length < 0 Then
SafeRight = ""
Exit Function
End If

If length = 0 Then
SafeRight = ""
ElseIf length >= Len(text) Then
SafeRight = text
Else
SafeRight = Right(text, length)
End If
End Function

Performance Considerations

• Right is a very fast string function
• Performance is O(n) where n is the length parameter
• More efficient than using Mid to extract from the end
• For large strings, consider caching Len(string) if called multiple times
• No significant performance difference between Right and string slicing

Best Practices

1. Validate Length: Check that length parameter is valid before calling
2. Handle Null: Check for Null strings if data source is uncertain
3. Use with InStrRev: Combine with InStrRev for finding from right
4. Document Intent: Make clear why extracting from right vs left
5. Consider Edge Cases: Handle empty strings, length = 0, length > string length
6. Use for File Extensions: Preferred method for extracting file extensions
7. Combine with Trim: Often useful to Trim before using Right
8. Cache String Length: If using Len(string) multiple times, cache it
9. Avoid Magic Numbers: Use named constants for length values
10. Test Boundary Conditions: Test with length = 0, 1, Len(string), Len(string)+1

Comparison with Related Functions

Platform and Version Notes

• Available in all versions of VB6 and VBA
• Behavior consistent across all platforms
• In VB.NET, replaced by String.Substring or string slicing
• RightB and RightB$ variants exist for byte data
• Right$ returns String type, Right returns Variant

Limitations

• Cannot use negative length to count from a different position
• No built-in way to extract "all but first N" characters (use Len arithmetic)
• Raises error on negative length instead of returning empty string
• No case-insensitive comparison built-in
• No Unicode-aware variant (uses ANSI/DBCS)

Related Functions

• Left: Returns characters from the left side of a string
• Mid: Returns characters from any position in a string
• InStrRev: Finds position of substring searching from right to left
• Len: Returns the length of a string
• RTrim: Removes trailing spaces from a string
• InStr: Finds position of substring searching from left to right