How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops vba vba

How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops


Regular expressions are used for Pattern Matching.

To use in Excel follow these steps:

Step 1: Add VBA reference to "Microsoft VBScript Regular Expressions 5.5"

  • Select "Developer" tab (I don't have this tab what do I do?)
  • Select "Visual Basic" icon from 'Code' ribbon section
  • In "Microsoft Visual Basic for Applications" window select "Tools" from the top menu.
  • Select "References"
  • Check the box next to "Microsoft VBScript Regular Expressions 5.5" to include in your workbook.
  • Click "OK"

Step 2: Define your pattern

Basic definitions:

- Range.

  • E.g. a-z matches an lower case letters from a to z
  • E.g. 0-5 matches any number from 0 to 5

[] Match exactly one of the objects inside these brackets.

  • E.g. [a] matches the letter a
  • E.g. [abc] matches a single letter which can be a, b or c
  • E.g. [a-z] matches any single lower case letter of the alphabet.

() Groups different matches for return purposes. See examples below.

{} Multiplier for repeated copies of pattern defined before it.

  • E.g. [a]{2} matches two consecutive lower case letter a: aa
  • E.g. [a]{1,3} matches at least one and up to three lower case letter a, aa, aaa

+ Match at least one, or more, of the pattern defined before it.

  • E.g. a+ will match consecutive a's a, aa, aaa, and so on

? Match zero or one of the pattern defined before it.

  • E.g. Pattern may or may not be present but can only be matched one time.
  • E.g. [a-z]? matches empty string or any single lower case letter.

* Match zero or more of the pattern defined before it.

  • E.g. Wildcard for pattern that may or may not be present.
  • E.g. [a-z]* matches empty string or string of lower case letters.

. Matches any character except newline \n

  • E.g. a. Matches a two character string starting with a and ending with anything except \n

| OR operator

  • E.g. a|b means either a or b can be matched.
  • E.g. red|white|orange matches exactly one of the colors.

^ NOT operator

  • E.g. [^0-9] character can not contain a number
  • E.g. [^aA] character can not be lower case a or upper case A

\ Escapes special character that follows (overrides above behavior)

  • E.g. \., \\, \(, \?, \$, \^

Anchoring Patterns:

^ Match must occur at start of string

  • E.g. ^a First character must be lower case letter a
  • E.g. ^[0-9] First character must be a number.

$ Match must occur at end of string

  • E.g. a$ Last character must be lower case letter a

Precedence table:

Order  Name                Representation1      Parentheses         ( )2      Multipliers         ? + * {m,n} {m, n}?3      Sequence & Anchors  abc ^ $4      Alternation         |

Predefined Character Abbreviations:

abr    same as       meaning\d     [0-9]         Any single digit\D     [^0-9]        Any single character that's not a digit\w     [a-zA-Z0-9_]  Any word character\W     [^a-zA-Z0-9_] Any non-word character\s     [ \r\t\n\f]   Any space character\S     [^ \r\t\n\f]  Any non-space character\n     [\n]          New line

Example 1: Run as macro

The following example macro looks at the value in cell A1 to see if the first 1 or 2 characters are digits. If so, they are removed and the rest of the string is displayed. If not, then a box appears telling you that no match is found. Cell A1 values of 12abc will return abc, value of 1abc will return abc, value of abc123 will return "Not Matched" because the digits were not at the start of the string.

Private Sub simpleRegex()    Dim strPattern As String: strPattern = "^[0-9]{1,2}"    Dim strReplace As String: strReplace = ""    Dim regEx As New RegExp    Dim strInput As String    Dim Myrange As Range        Set Myrange = ActiveSheet.Range("A1")        If strPattern <> "" Then        strInput = Myrange.Value                With regEx            .Global = True            .MultiLine = True            .IgnoreCase = False            .Pattern = strPattern        End With                If regEx.Test(strInput) Then            MsgBox (regEx.Replace(strInput, strReplace))        Else            MsgBox ("Not matched")        End If    End IfEnd Sub

Example 2: Run as an in-cell function

This example is the same as example 1 but is setup to run as an in-cell function. To use, change the code to this:

Function simpleCellRegex(Myrange As Range) As String    Dim regEx As New RegExp    Dim strPattern As String    Dim strInput As String    Dim strReplace As String    Dim strOutput As String            strPattern = "^[0-9]{1,3}"        If strPattern <> "" Then        strInput = Myrange.Value        strReplace = ""                With regEx            .Global = True            .MultiLine = True            .IgnoreCase = False            .Pattern = strPattern        End With                If regEx.test(strInput) Then            simpleCellRegex = regEx.Replace(strInput, strReplace)        Else            simpleCellRegex = "Not matched"        End If    End IfEnd Function

Place your strings ("12abc") in cell A1. Enter this formula =simpleCellRegex(A1) in cell B1 and the result will be "abc".

results image


Example 3: Loop Through Range

This example is the same as example 1 but loops through a range of cells.

Private Sub simpleRegex()    Dim strPattern As String: strPattern = "^[0-9]{1,2}"    Dim strReplace As String: strReplace = ""    Dim regEx As New RegExp    Dim strInput As String    Dim Myrange As Range        Set Myrange = ActiveSheet.Range("A1:A5")        For Each cell In Myrange        If strPattern <> "" Then            strInput = cell.Value                        With regEx                .Global = True                .MultiLine = True                .IgnoreCase = False                .Pattern = strPattern            End With                        If regEx.Test(strInput) Then                MsgBox (regEx.Replace(strInput, strReplace))            Else                MsgBox ("Not matched")            End If        End If    NextEnd Sub

Example 4: Splitting apart different patterns

This example loops through a range (A1, A2 & A3) and looks for a string starting with three digits followed by a single alpha character and then 4 numeric digits. The output splits apart the pattern matches into adjacent cells by using the (). $1 represents the first pattern matched within the first set of ().

Private Sub splitUpRegexPattern()    Dim regEx As New RegExp    Dim strPattern As String    Dim strInput As String    Dim Myrange As Range        Set Myrange = ActiveSheet.Range("A1:A3")        For Each C In Myrange        strPattern = "(^[0-9]{3})([a-zA-Z])([0-9]{4})"                If strPattern <> "" Then            strInput = C.Value                        With regEx                .Global = True                .MultiLine = True                .IgnoreCase = False                .Pattern = strPattern            End With                        If regEx.test(strInput) Then                C.Offset(0, 1) = regEx.Replace(strInput, "$1")                C.Offset(0, 2) = regEx.Replace(strInput, "$2")                C.Offset(0, 3) = regEx.Replace(strInput, "$3")            Else                C.Offset(0, 1) = "(Not matched)"            End If        End If    NextEnd Sub

Results:

results image


Additional Pattern Examples

String   Regex Pattern                  Explanationa1aaa    [a-zA-Z][0-9][a-zA-Z]{3}       Single alpha, single digit, three alpha charactersa1aaa    [a-zA-Z]?[0-9][a-zA-Z]{3}      May or may not have preceding alpha charactera1aaa    [a-zA-Z][0-9][a-zA-Z]{0,3}     Single alpha, single digit, 0 to 3 alpha charactersa1aaa    [a-zA-Z][0-9][a-zA-Z]*         Single alpha, single digit, followed by any number of alpha characters</i8>    \<\/[a-zA-Z][0-9]\>            Exact non-word character except any single alpha followed by any single digit


To make use of regular expressions directly in Excel formulas the following UDF (user defined function) can be of help. It more or less directly exposes regular expression functionality as an excel function.

How it works

It takes 2-3 parameters.

  1. A text to use the regular expression on.
  2. A regular expression.
  3. A format string specifying how the result should look. It can contain $0, $1, $2, and so on. $0 is the entire match, $1 and up correspond to the respective match groups in the regular expression. Defaults to $0.

Some examples

Extracting an email address:

=regex("Peter Gordon: some@email.com, 47", "\w+@\w+\.\w+")=regex("Peter Gordon: some@email.com, 47", "\w+@\w+\.\w+", "$0")

Results in: some@email.com

Extracting several substrings:

=regex("Peter Gordon: some@email.com, 47", "^(.+): (.+), (\d+)$", "E-Mail: $2, Name: $1")

Results in: E-Mail: some@email.com, Name: Peter Gordon

To take apart a combined string in a single cell into its components in multiple cells:

=regex("Peter Gordon: some@email.com, 47", "^(.+): (.+), (\d+)$", "$" & 1)=regex("Peter Gordon: some@email.com, 47", "^(.+): (.+), (\d+)$", "$" & 2)

Results in: Peter Gordon some@email.com ...

How to use

To use this UDF do the following (roughly based on this Microsoft page. They have some good additional info there!):

  1. In Excel in a Macro enabled file ('.xlsm') push ALT+F11 to open the Microsoft Visual Basic for Applications Editor.
  2. Add VBA reference to the Regular Expressions library (shamelessly copied from Portland Runners++ answer):
    1. Click on Tools -> References (please excuse the german screenshot)Tools -> References
    2. Find Microsoft VBScript Regular Expressions 5.5 in the list and tick the checkbox next to it.
    3. Click OK.
  3. Click on Insert Module. If you give your module a different name make sure the Module does not have the same name as the UDF below (e.g. naming the Module Regex and the function regex causes #NAME! errors).

    Second icon in the icon row -> Module

  4. In the big text window in the middle insert the following:

    Function regex(strInput As String, matchPattern As String, Optional ByVal outputPattern As String = "$0") As Variant    Dim inputRegexObj As New VBScript_RegExp_55.RegExp, outputRegexObj As New VBScript_RegExp_55.RegExp, outReplaceRegexObj As New VBScript_RegExp_55.RegExp    Dim inputMatches As Object, replaceMatches As Object, replaceMatch As Object    Dim replaceNumber As Integer    With inputRegexObj        .Global = True        .MultiLine = True        .IgnoreCase = False        .Pattern = matchPattern    End With    With outputRegexObj        .Global = True        .MultiLine = True        .IgnoreCase = False        .Pattern = "\$(\d+)"    End With    With outReplaceRegexObj        .Global = True        .MultiLine = True        .IgnoreCase = False    End With    Set inputMatches = inputRegexObj.Execute(strInput)    If inputMatches.Count = 0 Then        regex = False    Else        Set replaceMatches = outputRegexObj.Execute(outputPattern)        For Each replaceMatch In replaceMatches            replaceNumber = replaceMatch.SubMatches(0)            outReplaceRegexObj.Pattern = "\$" & replaceNumber            If replaceNumber = 0 Then                outputPattern = outReplaceRegexObj.Replace(outputPattern, inputMatches(0).Value)            Else                If replaceNumber > inputMatches(0).SubMatches.Count Then                    'regex = "A to high $ tag found. Largest allowed is $" & inputMatches(0).SubMatches.Count & "."                    regex = CVErr(xlErrValue)                    Exit Function                Else                    outputPattern = outReplaceRegexObj.Replace(outputPattern, inputMatches(0).SubMatches(replaceNumber - 1))                End If            End If        Next        regex = outputPattern    End IfEnd Function
  5. Save and close the Microsoft Visual Basic for Applications Editor window.


Expanding on patszim's answer for those in a rush.

  1. Open Excel workbook.
  2. Alt+F11 to open VBA/Macros window.
  3. Add reference to regex under Tools then References
    ![Excel VBA Form add references
  4. and selecting Microsoft VBScript Regular Expression 5.5
    ![Excel VBA add regex reference
  5. Insert a new module (code needs to reside in the module otherwise it doesn't work).
    ![Excel VBA insert code module
  6. In the newly inserted module,
    ![Excel VBA insert code into module
  7. add the following code:

    Function RegxFunc(strInput As String, regexPattern As String) As String    Dim regEx As New RegExp    With regEx        .Global = True        .MultiLine = True        .IgnoreCase = False        .pattern = regexPattern    End With    If regEx.Test(strInput) Then        Set matches = regEx.Execute(strInput)        RegxFunc = matches(0).Value    Else        RegxFunc = "not matched"    End IfEnd Function
  8. The regex pattern is placed in one of the cells and absolute referencing is used on it.![Excel regex function in-cell usageFunction will be tied to workbook that its created in.
    If there's a need for it to be used in different workbooks, store the function in Personal.XLSB


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