I have some user input that I want to validate for correctness. The user should input 1 or more sets of characters, separated by commas.
So these are valid input
COM1
COM1,COM2,1234
these are invalid
COM -- only 3 characters
COM1,123 -- one set is only 3 characters
COM1.1234,abcd -- a dot separator not comma
I googled for a regex pattern to this and found a possible pattern that tested for a recurring instance of any 3 characters, and I modified like so
/^(.{4,}).*\1$/
but this is not finding matches.
I can manage the last comma that may or may not be there before passing to the test so that it is always there.
Preferably, I would like to test for letters (any case) and numbers only, but I can live with any characters.
I know I could easily do this in straight VBA splitting the input on a comma delimiter and looping through each character of each array element, but regex seems more efficient, and I will have more cases than have slightly different patterns, so parameterising the regex for that would be better design.
TIA
I believe this does what you want:
^([A-Z|a-z|0-9]{4},)*[A-Z|a-z|0-9]{4}$
It's a line beginning followed by zero or more groups of four letters or numbers ending with a comma, followed by one group of four letters or number followed by an end-of-line.
You can play around with it here: https://regex101.com/r/Hdv65h/1
The regular expression
"^[\w]{4}(,[\w]{4})*$"
should work.
You can try this to see whether it works for all your cases using the following function. Assuming your test strings are in cells A1 thru A5 on the spreadsheet:
Sub findPattern()
Dim regEx As New RegExp
regEx.Global = True
regEx.IgnoreCase = True
regEx.Pattern = "^[\w]{4}(,[\w]{4})*$"
Dim i As Integer
Dim val As String
For i = 1 To 5:
val = Trim(Cells(i, 1).Value)
Set mat = regEx.Execute(val)
If mat.Count = 0 Then
MsgBox ("No match found for " & val)
Else
MsgBox ("Match found for " & val)
End If
Next
End Sub
Related
I need a regular expression to match page numbers as found in common programs.
These usually take the form 1-5,3,5,1-9 for example.
I have a regular expression (\d+-\d+)?,(\d+-\d+?)* which I need help to refine.
As can be seen here regex101 I am matching commas and missing numbers entirely.
What I need is to match 1-5 as group 1, 3 as group 2, 5 as group 3 and 1-9 as group 4 without matching any commas.
Any help is appreciated. I will be using this in VBA.
This worked for me - am I missing something?
Sub Pages()
Dim re As Object, allMatches, m, rv, sep, c As Range, i As Long
Set re = CreateObject("VBScript.RegExp")
re.Pattern = "(\d+(-\d+)?)"
re.ignorecase = True
re.MultiLine = True
re.Global = True
For Each c In Range("B5:B20").Cells 'for example
c.Offset(0, 1).Resize(1, 10).ClearContents 'clear output cells
i = 0
If re.test(c.Value) Then
Set allMatches = re.Execute(c.Value)
For Each m In allMatches
i = i + 1
c.Offset(0, i).Value = m
Next m
End If
Next c
End Sub
If I recall correctly, capturing a dynamic number of groups will not work. You can pre-specify the format / number of groups to be matched, or you can catch the repeated groups as one and split them afterwards.
If you know the format, just do
(\d+(?:-\d+)?)(?:,)(\d+(?:-\d+)?)(?:,)(\d+(?:-\d+)?)(?:,)(\d+(?:-\d+)?)
which of course is not very neat.
If you want the flexible structure, match the first group and all the rest as a second and then split the latter by the delimiter ',' in whichever language.
(\d+(?:-\d+)?)((?:(?:,)(\d+(?:-\d+)?))*)
You need to make the -\d+ part optional, since you don't always have ranges. And the comma between each range should be part of the second group with the * quantifier, so you can match a single range with no comma after it.
\d+(-\d+)?(,\d+(-\d+)?)*
This will match the string that contains all the ranges. To get an array of individual ranges without the commas, do a second match in this string:
\d+(-\d+)?
Use the VBA function for getting an array of all matches of a regexp (sorry, I don't know VBA, so can't provide the specific syntax).
I am writing an Excel Add In to read a text file, extract values and write them to an Excel file. I need to split a line, delimited by one or more white spaces and store it in the form of array, from which I want to extract desired values.
I am trying to implement something like this:
arrStr = Split(line, "/^\s*/")
But the editor is throwing an error while compiling.
How can I do what I want?
If you are looking for the Regular Expressions route, then you could do something like this:
Dim line As String, arrStr, i As Long
line = "This is a test"
With New RegExp
.Pattern = "\S+"
.Global = True
If .test(line) Then
With .Execute(line)
ReDim arrStr(.Count - 1)
For i = 0 To .Count - 1
arrStr(i) = .Item(i)
Next
End With
End If
End With
IMPORTANT: You will need to create a reference to:
Microsoft VBScript Regular Expressions 5.5 in Tools > References
Otherwise, you can see Late Binding below
Your original implementation of your original pattern \^S*\$ had some issues:
S* was actually matching a literal uppercase S, not the whitespace character you were looking for - because it was not escaped.
Even if it was escaped, you would have matched every string that you used because of your quantifier: * means to match zero or more of \S. You were probably looking for the + quantifier (one or more of).
You were good for making it greedy (not using *?) since you were wanting to consume as much as possible.
The Pattern I used: (\S+) is placed in a capturing group (...) that will capture all cases of \S+ (all characters that are NOT a white space, + one or more times.
I also used the .Global so you will continue matching after the first match.
Once you have captured all your words, you can then loop through the match collection and place them into an array.
Late Binding:
Dim line As String, arrStr, i As Long
line = "This is a test"
With CreateObject("VBScript.RegExp")
.Pattern = "\S+"
.Global = True
If .test(line) Then
With .Execute(line)
ReDim arrStr(.Count - 1)
For i = 0 To .Count - 1
arrStr(i) = .Item(i)
Next
End With
End If
End With
Miscellaneous Notes
I would have advised just to use Split(), but you stated that there were cases where more than one consecutive space may have been an issue. If this wasn't the case, you wouldn't need regex at all, something like:
arrStr = Split(line)
Would have split on every occurance of a space
I am trying to use regex to 'extract' paragraphs in a document. Each paragraph is preceded and followed by a '-' on separate line and each paragraph starts with a number.
For example
-
1. This is a paragraph
It may go over multiple lines
-
Ideally, I would like to not include the '-', but it doesn't really matter as I will be placing it in a string and running another regex against it (One that I know works)
The code I am trying to use is basically as follows
Dim matchPara as Object
Dim regex as Object
Dim theMatch as Object
Dim matches as Object
Dim fileName as String
Dim fileNo as Integer
Dim document as String
matchPara = "-?(\d.*?)?-"
Set regex = CreateObject("VBScript.RegExp")
regex.Pattern = matchPara
regex.Global = True
regex.Multiline = True
fileName = "C:\file.txt"
fileNo = FreeFile
Open fileName For Input As #fileNo
document = Input$(LOF(fileNo), fileNo)
set matches = regex.Execute(document)
For Each theMatch in matches
MsgBox(theMatch.Value)
Next theMatch
Close #fileNo
I have tested this regex on regex101 and it appeared to do what I wanted. I have also tested it without the grouping
-?\d.*?-
However when I run the code the theMatch.Value only ever contains a single '-'. After some messing around with the regex I got it to display the first line of text but never any more than the first line.
I have checked the length of theMatch.Value with:
MsgBox(len(theMatch.Value))
and placed the contents of theMatch.Value in a cell on the worksheet to see if It was cutting off in the message box, but both theories were proved wrong.
I am at a complete loss now and I am beginning to suspect it is possibly a VBA thing and not a regex thing. There is no requirement to use regex, I just assumed it would be the easiest thing to do.
The paragraphs contain data that I am trying to extract. So the idea was to regex each paragraph out place that in a string then run other regex to get the information that I need. Some paragraphs wont contain the data that I need so the idea was to loop through each individual paragraph and then error handle better if the data I need wasn't in that paragraph (ie get what I can and drop the rest with an error message)
Here is a screenshot:
This simple approach does not use Regex. It assumes the data is in column A and the paragraphs are placed in column B:
Sub paragraph_no_regex()
Dim s As String
Dim ary
With Application.WorksheetFunction
s = .TextJoin(" ", False, Columns(1).SpecialCells(2))
End With
ary = Split(s, "-")
i = 1
For Each a In ary
Cells(i, 2) = a
i = i + 1
Next a
End Sub
Sub F()
Dim re As New RegExp
Dim sMatch As String
Dim document As String
re.Pattern = "-\n((.|\n)+?)\n-"
'Getting document
document = ...
sMatch = re.Execute(document)(0).SubMatches(0)
End Sub
If you need dashes -, then just include them into capture group (the outer parenthesis).
This RegEx matches your description and successfully extracts paragraphs (as tested on regex101.com):
matchPara = "-\n\d+\.\s*((?:.|\n)+?)\s*\n-"
It needs the 'global' flag but not the 'multiline' flag. Instead, the end-of-line token is matched in the regex. The main point is that the innermost matching group will match any character including the end-of-line (given as an alternative) but does so in a non-greedy way ("+?"). It doesn't care about word boundaries as this is not necessary here. Also, "-" is not a special character where used in the regex so it doesn't have to be escaped.
As added benefit leading and trailing whitespace is cut off ("\s*" outside the group).
I'm struggling to come up with a regular expression pattern that can help me determine if a string is a cell's address or if it is a cell's name.
Here are some examples of cell addresses:
"E5"
"AA55:E5"
"DD5555:DDD55555, E5, F5:AA55"
"$F7:$G$7"
Here are some examples of cell names:
"bis_document_id"
"PCR1MM_YPCVolume"
"sheet_error7"
"blahE5"
"training_A1"
"myNameIsGeorgeJR"
Is there a regex pattern you guys can come up with that will match all of either group and none of the other?
I have been able to think of a couple of ways to determine what a string is not:
If it has any other character than "$" or ":" in it, I know it is not a cell's name and is most likely a cell's address.
If it has more than three consecutive numbers, it is most likely not a cell's address.
A cell's address is extremely unlikely to have more than 2 letters preceding a number, 99.9% of the cell addresses will be in columns A to ZZ.
Alas, these three small tests can hardly prove what this string is.
Thanks for the help!
OK, this one's fun:
^\$?[A-Z]+\$?\d+(?::\$?[A-Z]+\$?\d+)?(?:,\s*(?:\$?[A-Z]+\$?\d+(?::\$?[A-Z]+\$?\d+)?))*$
Let's break it down, because it's rather nasty. The magic subpattern, really, is this:
\$?[A-Z]+\$?\d+
This little thing will match any single valid cell address, with optional absolute-value $s. The next bit,
(?::\$?[A-Z]+\$?\d+)?
will match the same thing optionally (the ? quantifier at the end), but preceded by a colon (:). That lets us get ranges. The next bit,
(?:,\s*(?:\$?[A-Z]+\$?\d+(?::\$?[A-Z]+\$?\d+)?))*
matches the same thing as the first, but zero or more times (using the * quantifier), and preceded by a comma and optional spaces using the special \s token (which means "any whitespace").
Demo on Regex101
If we want to get really fancy (and, mind you, I have no idea whether Excel's regex engine supports this; I just wrote it for fun), we can use recursion to accomplish the same thing:
^((\$?[A-Z]+\$?\d+)(?::(?2))?)(?:,\s*(?1))*$
In this case, the magic \$?[A-Z]+\$?\d+ is inside the second capturing group, which is used recursively by the (?2) token. The entire subpattern for a single address or range of them is contained within the first capture group, and is then used to match additional addresses or ranges in a list.
Demo on Regex101
So here's a regex for VBA which will find any cell reference irrespective where it is.
NOTE: I've assumed you're performing this on a Formula object and thus doesn't require being at the start or end of the string; so you can have a string with cell references and cell names and it will only pick up the cell references as below:
(?:\W|^)(\$?[A-Z]{1,3}\$?[0-9]{1,7}(:\$?[A-Z]{1,3}\$?[0-9]{1,7})?)(?!\w)
(?:\W|^) is at the start and ensures that there is a non-word character before it or the start of the string (remove |^ if it there is always a = at the start as in Formula objects) --- VBA I found out regrettably does not have a functioning negative lookbehind)
(\$?[A-Z]{1,3}\$?[0-9]{1,7}(:\$?[A-Z]{1,3}\$?[0-9]{1,7})?) finds the actual cell reference and is broken down below:
\$?[A-Z]{1,3}\$?[0-9]{1,7} matches to one to three capital letters (as applicable to Excel's possible current ranges;
(:\$?[A-Z]{1,3}\$?[0-9]{1,7})? is the same as above except it adds the option of a second cell reference after a column ? makes it optional.
(?!\w) is a negative look forward and says that the character after it must not be a word character (presumably in functions the only things you can have around a cell references are parentheses and operators).
I wrote a VBA function in Excel and it returned the following with the above RegEx:
NB: It doesn't pick up obviously if the characters are in the right order as the reference $AZO113:A4 is returned despite it being impossible.
After trying several solutions I had to modify a regex so it works for me. my version only support non-named ranges.
((?![\=,\(\);])(\w+!)|('.+'!))?((\$?[A-Z]{1,3}\$?[0-9]{1,7}(:\$?[A-Z]{1,3}\$?[0-9]{1,7})?)|(\$?[A-Z]{1,3}(:\$?[A-Z]{1,3}\$?)))
It will capture ranges in all of the following situations
=FUNCTION(F:F)
=FUNCTION($B22,G$5)
=SUM($F$10:$F$11)
=$J10-$K10
=SUMMARY!D4
I created the following function for RegEx. but first tick the reference to "Microsoft VBScript Regular Expressions 5.5" from Tools>References
Function RegExp(ByVal sText As String, ByVal sPattern, Optional bGlobal As Boolean = True, Optional bIgnoreCase As Boolean = False, Optional bArray As Boolean = False) As Variant
Dim objRegex As New RegExp
Dim Matches As MatchCollection
Dim Match As Match
Dim i As Integer
objRegex.IgnoreCase = bIgnoreCase
objRegex.Global = bGlobal
objRegex.Pattern = sPattern
If objRegex.test(sText) Then
Set Matches = objRegex.Execute(sText)
If Matches.count <> 0 Then
If bArray Then ' if we want to return array instead of MatchCollection
ReDim aMatches(Matches.count - 1) As Variant
For Each Match In Matches
aMatches(i) = Match.value
i = i + 1
Next
RegExp = aMatches
Else
Set RegExp = Matches
End If
End If
End If
End Function
I have written a small program to whir through a textfile and find and replace regex where 9 digits \d{9}. It works fine, except what I need is a little more complicated.
I am finding the right data correctly. theFile is just a string with the text file streamread into it. I do this and then create and write it to another file.
But I need to find each string match individually, and replace that match with only the last 5 digits of that individual number (currently this is just replacing with FOUND). Keeping the file otherwise identical.
I am not sure how/what is the best way of doing this? would i have to split into an array of strings rather than one mass string? (it's quite a big file)
Any questions let me know, thanks in advance.
Dim regexString As String = "(\d{9})"
Dim replacement1 As String = "FOUND"
Dim rgx As New Regex(regexString)
Try
theFile = rgx.Replace(theFile, replacement1)
Catch
End try
Instead of using just one replacement pattern \d{9} split and group with two patterns, the first is 4 numbers long, the second 5 numbers. Then in the replace use only the last 5 numbers from the last group
Dim k = "abcd 123456789 abcf"
Dim ptn = "(\d{4})(\d{5})"
Dim result = Regex.Replace(k, ptn, "$2")
This approach leaves unchanged the sequences with less than 9 consecutive numbers, but if you have sequences with more than 9 numbers and don't want to change them, then you need a pattern with
Dim ptn = "(\b\d{4})(\d{5}\b)"
to fix the two groups inside a sequence of exactly nine numbers.
The question appears to ask for matches on exactly nine digits and wants the first four to be removed. Ie to replace the nine digits with the last five.
Splitting the regular expression in the question into two parts, for the unwanted and the wanted parts gives
regexString = "\d{4}(\d{5})"
which captures the wanted five digits, so then the replacement is
replacement1 ="$1"
Or in some other regular expression implementations it would be replacement1 ="\1". Additionally the replace method in some regular expression system may have additional options (parameters) for replace first versus replace n-th versus replace all occurrences.
Suppose there are more than nine digits and only the final five are wanted. In this case the regular expression can be written as one of the following (as different regular expression languages support different features). The replacement expression is the same as above.
regexString = "\d{4,}(\d{5})"
regexString = "\d\d\d\d+(\d{5})"
regexString = "\d\d\d\d\d*(\d{5})"
Because regular expressions are normally "greedy" the \d{5} should always match the final 5 digits but it may be worth finishing the regular expression with ...(\d{5})([^\d]|$) and changing the replace to be $1$2. That way it looks for a trailing non-digit or end-of-string.