I'm heaving trouble finding the right regex for decimal numbers which include the comma separator.
I did find a few other questions regarding this issue in general but none of the answers really worked when I tested them
The best I got so far is:
[0-9]{1,3}(,([0-9]{3}))*(.[0-9]+)?
2 main problems so far:
1) It records numbers with spaces between them "3001 1" instead of splitting them to 2 matches "3001" "1" - I don't really see where I allowed space in the regex.
2) I have a general problem with the beginning\ending of the regex.
The regex should match:
3,001
1
32,012,111.2131
But not:
32,012,11.2131
1132,012,111.2131
32,0112,111.2131
32131
In addition I'd like it to match:
1.(without any number after it)
1,(without any number after it)
as 1
(a comma or point at the end of the number should be overlooked).
Many Thanks!
.
This is a very long and convoluted regular expression that fits all your requirements. It will work if your regex engine is based on PCRE (hopefully you're using PHP, Delphi or R..).
(?<=[^\d,.]|^)\d{1,3}(,(\d{3}))*((?=[,.](\s|$))|(\.\d+)?(?=[^\d,.]|$))
DEMO on RegExr
The things that make it so long:
Matching multiple numbers on the same line separated by only 1 character (a space) whilst not allowing partial matchs requires a lookahead and a lookbehind.
Matching numbers ending with . and , without including the . or , in the match requires another lookahead.
(?=[,.](\s|$)) Explanation
When writing this explanation I realised the \s needs to be a (\s|$) to match 1, at the very end of a string.
This part of the regex is for matching the 1 in 1, or the 1,000 in 1,000. so let's say our number is 1,000. (with the . on the end).
Up to this point the regex has matched 1,000, then it can't find another , to repeat the thousands group so it moves on to our (?=[,.](\s|$))
(?=....) means its a lookahead, that means from where we have matched up to, look at whats coming but don't add it to the match.
So It checks if there is a , or a . and if there is, it checks that it's immediately followed by whitespace or the end of input. In this case it is, so it'd leave the match as 1,000
Had the lookahead not matched, it would have moved on to trying to match decimal places.
This works for all the ones that you have listed
^[0-9]{1,3}(,[0-9]{3})*(([\\.,]{1}[0-9]*)|())$
. means "any character". To use a literal ., escape it like this: \..
As far as I know, that's the only thing missing.
Related
I think this is a simple thing for a lot of you, but I have a very limited knowlegde of regex at the moment. I want to match everything except a double digit number in a string.
For example:
TEST22KLO4567
QE45C2C
LOP10G7G400
Now I found out the regex to match the double digit numbers:
\d{2}
Which matches the following:
TEST22KLO4567
QE45C2C
LOP10G7G400
Now it seems to me that it would be fairly easy to turn that regex around to match everything BUT "\d{2}". I searched a lot but I can't seem to get it done. I hope someone here can help.
This only works if your regex engine supports look behinds:
^.+?(?=\d{2})|(?<=\d{2}).+$
Explanation:
The | separates two cases where this would match:
^.+?(?=\d{2})
This matches everything from the start of the string (^) until \d{2} is encountered.
(?<=\d{2}).+$
This matches the end of the string, from the place just after two digits.
If your regex engine doesn't support look behinds (JavaScript for example), I don't think it is possible using a pure regex solution.
You can match the first part:
^.+?(?=\d{2})
Then get where the match ends, add 2 to that number, and get the substring from that index.
You are right rejecting a search in regex is usually rather tricky.
In your case I think you want to have [^\d{2}], however, this is tricky as your other strings also contain two digits so your regex using it won't select them.
I would go with this regex (using PCRE 8.36 but should work also in others):
\*{2}\w*\*{2}
Explanation:
\*{2} .... matches "*" literally exactly two times
\w* .... matches "word character" zero or unlimited times
Found one regex pretty straightforward :
^(.*?[^\d])\d{2}([^\d].*?)$
Explanations :
^ : matches the beginnning of a line
(.*?[^\d]) : matches and catches the first part before the two numbers. It can contain anything (.*?) but needs to end with something different to a number ([^\d]) so we ensure that there is only 2 numbers in the middle
\d{2} : is the part you found yourself
([^\d].*?) : is the symetric of (.*?[^\d]) : begins with something different from a number ([^\d]) and matches anything next.
$ : up to the end of the line.
To test this reges you can use this link
It will match the first occurence of double digit, but because OP said there was only one it does the job correctly. I expect it to work with every regex engine as nothing too complex is used.
I'm trying to detect a price in regex with this:
^\-?[0-9]+(,[0-9]+)?(\.[0-9]+)?
This covers:
12
12.5
12.50
12,500
12,500.00
But if I pass it
12..50 or 12.5.0 or 12.0.
it still returns a match on the 12 . I want it to negate the entire string and return no match at all if there is more than one period in the entire string.
I've been trying to get my head around negative lookaheads for an hour and have searched on Stack Overflow but can't seem to find the right answer. How do I do this?
What you are looking for, is this:
^\d+(,\d{3})*(\.\d{1,2})?$
What it does:
^ Start of Line
\d+ one or more Digits followed by
(,\d{3})* zero, one or more times a , followed by three Digits followed by
(\.\d{1,2})? one or zero . followed by one or two Digits followed by
$ End of Line
This will only match valid Prices. The Comma (,) is not obligatory in this Regex, but it will be matched.
Look here: http://www.regextester.com/?fam=98001
If you work with Prices and want to store them in a Database I recommend saving them as INT. So 1,234,56 becomes 123456 or 1,234 becomes 123400. After you matched the valid price, all you have to do is to remove the ,s, split the Value by the Dot, and fill the Value of [1] with str_pad() (STR_PAD_RIGHT) with Zeros. This makes Calculations easier, in special when you work with Javascript or other different Languages.
Your regex:
^\-?[0-9]+(,[0-9]+)?(\.[0-9]+)?
Note: The regex you provided does not seem to work for 12 (without "."). Since you didn't add a quantifier after \., it tries to match that pattern literally (.).
While there are multiple ways to solve this and the most "correct" answer will depend on your specific requirements, here's a regex that will not match 12..1, but will match 12.1:
(^\-?[0-9]+(?:,[0-9]+)?(?:\.[0-9]+))+
I surrounded the entire regex you provided in a capturing group (...), and added a one or more quantifier + at the end, so that the entire regex will fail if it does not satisfy that pattern.
Also (this may or may not be what you want), I modified the inner groups into non-capturing groups (?: ... ) so that it does not return unnecessary groups.
This site offers a deconstruction of regexes and explains them:
For the regex provided: https://regex101.com/r/EDimzu/2
Unit tests: https://regex101.com/r/EDimzu/2/tests (Note the 12 one's failure for multiple languages).
You can limit it by requiring there is only 0 or 1 periods like this:
^[0-9,]+[\.]{0,1}?[0-9,]+$
I need some assistance constructing a regular expression in a ColdFusion application. I apologize if this has been asked. I have searched, but I may not be asking for the correct thing.
I am using the following to search an email subject line for an issue number:
reMatchNoCase("[0-9]{5}", mailCheck.subject)
The issue number contains only numeric values, and should be exactly 5 digits. This is working except in cases where I have a longer number that appears in the string, such as 34512345. It takes the first 5 digits of that string as a valid issue number as well.
What I want is to retrieve only 5 digit numbers, nothing shorter or longer. I am then placing these into a list to be looped over and processed. Do I perhaps need to include spaces before and after in the regex to get the desired result?
Thank you.
The general way to exclude content from occurring before/after a match is to use negative lookbehind before the match and a negative lookahead afterwards. To do this for numeric digits would be:
(?<!\d)\d{5}(?!\d)
(Where \d is the shorthand for [0-9])
CF's regex supports lookaheads, but unfortunately not lookbehinds, so that wouldn't work directly in rematch - however that probably doesn't matter in this case because it's likely that you don't want, for example, abc12345 to match either - so what you more likely want is:
\b\d{5}\b
Where \b is a "word boundary" - roughly, it checks for a change between a "word character" and a non-word character (or visa versa) - so in this case the first \b will check that there is NOT one of [a-zA-Z0-9_] before the first digit, and the second \b will check that there isn't one after the fifth digit. A \b does not append any characters to the match (i.e. it is a zero-width assertion).
Since you're not dealing with case, you don't need the nocase variable and can simply write:
rematch( '\b\d{5}\b' , mailCheck.subject )
The benefit of this over simply checking for spaces is that the result is five digits (no need to trim), but the downside is that it would match values such as [12345] or 3.14159^2 which are probably not what you want?
To check for spaces, or the start/end of the string, you can do:
rematch( '(?:^| )\d{5}(?= |$)' , mailCheck.subject )
Then use trim on each result to remove spaces.
If that's not what you're after, go ahead and provide more details.
I have a set of strings separated with commas,
like : cat,dog,Elephant
what to validate is like strings separated with commas should
range from length of 3 to 6 . (strings can be anything like .&^*#$)
i.e a9&,bbbb,cc,ddddddd
in the above strings cc,ddddddd are invalid since dint come into
the range of length 3 t0 6.
In this way a9&,bbbb,ccc,a12$%,adsdff
I went through many question that where posted in stack overflow
and got some ideas from it
^[1-9]\d([,][1-9]\d){0,3}$ this is a regex i got from stackoverflow posted question
this accepts digits alone but I need alphanumeric
I tired to change but dint work
^1-9a-zA-z{0,3}$
Could you please help me out?
and explain what does each symbol means so that i could learn more from
you people.
Thank you for posting answers for my previous questions too.
[^,] will accept everything BUT the comma that you are using as a separator. It isn't clear what your regex should give you, if the substrings that are not long 3-6, the substrings that ARE long 3-6, both mixed, both divided or what.
Try this:
Regex rx = new Regex("^(?:(?:([^,]{3,6})|(?:[^,]*))(?:,|$))*");
var matches = rx.Match("AA,BB&B,!CC,DDDDDD,EE");
foreach (Capture capture in matches.Groups[1].Captures) {
string oneCapture = capture.Value;
}
The captures will be only the strings that are long 3-6.
I believe what you want is the following;
^([^,]{3,6},)*[^,]{3,6}$
To break this down the first ^ matches the beginning of a line the [^,]{3,6}, means 3 to 6 characters of anything but a comma followed by a single comma. the ( )* enclosing that means repeat this 0 or more times then the last [^,]{3,6}$ part says end this with 3 to 6 characters which aren't a comma.
This should do the trick if the regex you mentioned already works fine for digits.
^.\d([,].\d){0,3}$
For reference I often use msdn reference, but it's kept a bit short to begin with, maybe someone else can provide a good tutorial.
There are some tools out there like expresso which help test and develop regexes.
I think the following expression does what you want:
^(?:([^,]{3,6}),?)*$
The [^,]{3,6} part means "any character that is not a comma, 3 to 6 repetitions". That is the core of the expression. The parenthesis make a group, which will allow you to retrieve the values that were captured by that group.
The ,? part means "a comma, zero or one times".
These parts are surrounded by a non-capturing group (?: ... ). That means that the contained expression is grouped, but you won't be able to retrieve the values that were captured by it. That group is necessary to apply a repetition charater *, which means "repeat the previous group zero or more times".
The anchors ^ and $ mean "beginning of string" and "end of string". They prevent the expression from matching only part of a string. If you were searching for a pattern inside a larger string, you wouldn't want them.
You might want to try Expresso to learn more about regular expressions. The program has an analyzer that describes the various parts of the expression.
I've got the following url route and i'm wanting to make sure that a segment of the route will only accept numbers. as such, i can provide some regex which checks the word.
/page/{currentPage}
so.. can someone give me a regex which matches when the word is a number (any int) greater than 0 (ie. 1 <-> int.max).
/^[1-9][0-9]*$/
Problems with other answers:
/([1-9][0-9]*)/ // Will match -1 and foo1bar
#[1-9]+# // Will not match 10, same problems as the first
[1-9] // Will only match one digit, same problems as first
If you want it greater than 0, use this regex:
/([1-9][0-9]*)/
This'll work as long as the number doesn't have leading zeros (like '03').
However, I recommend just using a simple [0-9]+ regex, and validating the number in your actual site code.
This one would address your specific problem. This expression
/\/page\/(0*[1-9][0-9]*)/ or "Perl-compatible" /\/page\/(0*[1-9]\d*)/
should capture any non-zero number, even 0-filled. And because it doesn't even look for a sign, - after the slash will not fit the pattern.
The problem that I have with eyelidlessness' expression is that, likely you do not already have the number isolated so that ^ and $ would work. You're going to have to do some work to isolate it. But a general solution would not be to assume that the number is all that a string contains, as below.
/(^|[^0-9-])(0*[1-9][0-9]*)([^0-9]|$)/
And the two tail-end groups, you could replace with word boundary marks (\b), if the RE language had those. Failing that you would put them into non-capturing groups, if the language had them, or even lookarounds if it had those--but it would more likely have word boundaries before lookarounds.
Full Perl-compatible version:
/(?<![\d-])(0*[1-9]\d*)\b/
I chose a negative lookbehind instead of a word boundary, because '-' is not a word-character, and so -1 will have a "word boundary" between the '-' and the '1'. And a negative lookbehind will match the beginning of the string--there just can't be a digit character or '-' in front.
You could say that the zero-width assumption ^ is just one of the cases that satisfies the zero-width assumption (?<![\d-]).
string testString = #"/page/100";
string pageNumber = Regex.Match(testString, "/page/([1-9][0-9]*)").Groups[1].Value;
If not matched pageNumber will be ""
While Jeremy's regex isn't perfect (should be tested in context, against leading characters and such), his advice is good: go for a generic, simple regex (eg. if you must use it in Apache's mod_rewrite) but by any means, handle the final redirect in server's code (if you can) and do a real check of parameter's validity there.
Otherwise, I would improve Jeremy's expression with bounds: /\b([1-9][0-9]*)$/
Of course, a regex cannot provide a check against any max int, at best you can control the number of digits: /\b([1-9][0-9]{0,2})$/ for example.
This will match any string such that, if it contains /page/, it must be followed by a number, not consisting of only zeros.
^(?!.*?/page/([0-9]*[^0-9/]|0*/))
(?! ) is a negative look-ahead. It will match an empty string, only if it's contained pattern does not match from the current position.