How to check if word boundary has all zero using regex - regex

I am writing regex to validate contact number. I am using following regex for validation as :
^(?!\b(0)\1+\b)(?!(-))([+]?(\d{1,3})?[\s.-]?\(?\d{3}\)?[\s.-]?\d{3}[\s.-]?\d{4}$)
I do not want to match input like "+00 (000) 000-0000" using this regex.
The regex should not match "+00 (000) 000-0000".
I was trying to fix this by using "word boundary should not contains all zero" but not sure how to do it.
Please suggest how to fix this. Any pointer would help.
Thanks

You have whitespaces, (, ), + and - symbols allowed beside digits. So, if you prohibit the string to contain these symbols and 0 digit only, you will achieve the effect you want.
Add the (?![0\s()+-]+$) negative lookahead after ^ so that it could be executed at the very start of the string.
^(?![0\s()+-]+$)(?!-)([+]?(\d{1,3})?[\s.-]?\(?\d{3}\)?[\s.-]?\d{3}[\s.-]?\d{4}$)
See the regex demo.

If you want to reject the match if the phone number has all zeroes, you can enforce the presence of a non-zero number using a positive look ahead (?=.*[1-9])
^(?=.*[1-9])(?!-)([+]?(\d{1,3})?[\s.-]?\(?\d{3}\)?[\s.-]?\d{3}[\s.-]?\d{4}$)
^^^^^^^^^^^ This ensures the number have at least one non-zero number
Demo

Related

Regex not select word with character at the end

I have a simple question.
I need a regular expression to match a hexdecimal number without colon at the end.
For example:
0x85af6b9d: 0x00256f8a ;some more interesting code
// dont match 0x85af6b9d: at all, but match 0x00256f8a
My expression for hexdecimal number is 0[xX][0-9A-Fa-f]{1,8}
Version with (?!:) is not possible, because it will just match 0x85af6b9 (because of the {1,8} token)
Using a $ also isn't possible - there can be more numbers than one
Thanks!
Here is one way to do so:
0[xX][0-9A-Fa-f]{1,8}(?![0-9A-Fa-f:])
See the online demo.
We use a negative lookahead to match all hexadecimal numbers without : at the end. Because of {1,8}, it is also necessary to ensure that the entire hexadecimal number is correctly matched. We therefore reuse the character set ([0-9A-Fa-f]) to ensure that the number does not continue.

Regex that matches specific letters preceded by a percent sign and does not allow numbers. "%l%m%p"

I'm having trouble writing a regex that matches a pattern like this "%n%m%p" or "%n:%m%p". Only allow specific letters and each letter must have percent sign in front of it. No numbers allowed.
This regex /%(n|m|p)$/ works but allows numbers in between. For example this "%n3%p%m" matches. How do I disallow any numbers.
The regex %(n|m|p) itself matches either %n or %m or %p. That the numbers are allowed between each of the parts is most likely because of your other code.
You can match the whole with this regex
/^(%(n|m|p):{0,1}){0,}$/
Just need to be clear about the exact requirements.
The allowed letters are [nmp]
Each letter has to be preceded by a %
There can be an optional : before %
+ One or more tokens from ^ start to $ end
These requirements won't allow any digit.
^(?::?%[nmp])+$
You can test it at regex101
I can't leave a comment but I can answer, so...
It would help to know what exactly you need from this. Do you need those letters in that order? Do you need exactly 3? Or are you looking for any number of any length with any valid characters in between?
That said, one option if you're matching the entire string is
/^(%[nmp][^\d]*)+$/
which should match any %[nmp] with any character between them that isn't a number. Note though that this will match a single %n for example. If you want to match a specific number i or more than a certain number j, change the + to {i} or {j,} respectively.
As long as it has one of the letters and a percent sign it should
match. Just no numbers
Use the following regex pattern:
%[nmp](?!\d)\b
https://regex101.com/r/CrSnFp/2
(?!\d) - negative lookahead assertion, matches one of the specified characters if it's not followed by a number

Capture number between two whitespaces (RegEx)

I have the following data:
SOMEDATA .test 01/45/12 2.50 THIS IS DATA
and I want to extract the number 2.50 out of this. I have managed to do this with the following RegEx:
(?<=\d{2}\/\d{2}\/\d{2} )\d+.\d+
However that doesn't work for input like this:
SOMEDATA .test 01/45/12 2500 THIS IS DATA
In this case, I want to extract the number 2500.
I can't seem to figure out a regex rule for that. Is there a way to extract something between two spaces ? So extract the text/number after the date until the next whitespace ? All I know is that the date will always have the same format and there will always be a space after the text and then a space after the number I want to extract.
Can someone help me out on this ?
Capture number between two whitespaces
A whitespace is matched with \s, and non-whitespace with \S.
So, what you can use is:
\d{2}\/\d{2}\/\d{2} +(\S+)
^^^
See the regex demo
The 1+ non-whitespace symbols are captured into Group 1.
If - for some reason - you need to only get the value as a whole match, use your lookbehind approach:
(?<=\d{2}\/\d{2}\/\d{2} )\S+
Or - if you are using PCRE - you may leverage the match reset operator \K:
\d{2}\/\d{2}\/\d{2} +\K\S+
^^
See another demo
NOTE: the \K and a capture group approaches allow 1 or more spaces after the date and are thus more flexible.
I see some people helped you already, but if you would want an alternative working one for some reason, here's what works too :)
.+ \d+\/\d+\/\d+ (\d+[\.\d]*)
So the .+ matches anything plus the first space
then the \d+/\d+/\d+ is the date parsing plus a space
the capturing group is the number, as you can see I made the last part optional, so both floating point values and normal values can be matched. Hope this helped!
Proof: https://regex101.com/r/fY3nJ2/1
Just make the fractal part optional:
(?<=\d{2}\/\d{2}\/\d{2} )\d+(?:\.\d+)?
Demo: https://regex101.com/r/jH3pU7/1
Update following clarifications in comments:
To match anything (but space) surrounded by spaces and prepended by date use:
(?<=\d{2}\/\d{2}\/\d{2} )\S+
Demo: https://regex101.com/r/jH3pU7/3
Rather than capture, you can make your entire match be the target text by using a look behind:
(?<=\d\d(\/\d\d){2} )\S+
This matches the first series of non-whitespace that follows a "date like" part.
Note also the reduction in the length of the "date like" pattern. You may consider using this part of the regex in whatever solution you use.

ColdFusion Regex Match for Digits of Exact Length

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.

Need a simple RegEx to find a number in a single word

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.