I am trying to implement a regex for phone numbers, based on our business logic.
What the customer wants is that the phone must contain between 8 and 15 characters of numbers, and also can contain any spaces and dots anywhere which doesn't add to the count of numbers. So, theoretically this should be valid:
3 .... 44444444
Because it contains 9 numbers.
I can't really go further on
~[0-9\.\ ]{8,15}$
but obviously it counts dots and spaces to the limit too.
Is it even possible to implement it via regex?
A Regex attempt:
^(?:[ .]*\d){8,15}[ .]*$
This will match 8 to 15 digits, with any number of space or dot happening anywhere in between.
The non-captured group, (?:[ .]*\d), matches any digit preceded by any number of dot or space, {8,15} ensures the range on numbers
[ .]*$ matches any number of dot or space at the end
Demo
As far as I know, regular expressions cannot validate this. However you could maybe globally remove all whitespace and dots and then try to match a regex that is ^[[:digit:]]{8,15}$
Related
Newbie question but how can I check for instances where there are multiple numbers on the same line. For instance, the content reads for example contact 408-555-5454 or reach out to 408-555-4545. Right now the best I can do is ^4 but that's only catching multiple things if the mutliline flag is tured on. Any idea.
You could try the regex below
/4\d{2}(-| )?\d{3}(-| )?\d{4}/g
This of course assumes that you're looking for numbers that start with 4. You can have a look at the Regex Snippet here and you can experiment with trying different variations of the regex to suit your needs.
here's a key to the regex elements included:
4 = matches the literal number 4
\d{2} = matches 2 digits (0-9).
(-| )? = matches either a hyphen or single space but makes it not required. ie you can have a space or hyphen or not.
\d{3} = matches 3 digits (0-9)
Same as #3 above
\d{4} = matches 4 digits (0-9)
the g flag will ensure that you're searching through the whole text and not stopping after the first match.
If you like the answer please Accept it :)
I need a regular expression that will match a string that contains:
at least one number
zero or more letters
no other characters such as spaces
The string must also be a minimum of 8 characters and a maximum of 13 characters.
Placement of the numbers and/or letters within the 8-13 character string does not matter. I haven't figured out how to make sure that the string contains a number, but here are some expressions that don't work because they are picking up spaces in the online tool Regexr. Take a look below:
- ([\w^/s]){8,13}
- ([a-zA-Z0-9]){8,13}
- ([a-zA-Z\d]){8,13}
I am specifically looking to exclude spaces and special characters. The linked and related questions all appear to allow for these characters. This is not for validating passwords, it is for detecting case numbers in natural language processing. This is different from "Password REGEX with min 6 chars, at least one letter and one number and may contain special characters" because I am looking for at least one number but zero or more letters. I also do not want to return strings that contain any special characters including spaces.
This is a typical password validation with your requirements.
Note that this will also match 8-13 digits as well (but it is requested).
Ten million + 1 (and counting) happy customers ..
^(?=.*\d)[a-zA-Z\d]{8,13}$
Explained
^ # Beginning of string
(?= .* \d ) # Lookahead for a digit
[a-zA-Z\d]{8,13} # Consume 8 to 13 alphanum characters
$ # End of string
I've seen the answer above (by sln) everywhere over the internet, but as far as I can tell, it is NOT ACCURATE.
If your string contains 8 to 13 characters with no numbers this expression will match it, because it uses the * quantifier on the wildcard character . in the positive lookahead.
In order to match at least 1 digit, 1 A-Z and 1 a-z in a password that's at least 8 characters long, you'll need something like this:
(?=.{1,7}\d)(?=.{1,7}[a-z])(?=.{1,7}[A-Z])[a-zA-Z\d]{8,13}
it uses 3 lookaheads:
(?=.{1,7}\d)
(?=.{1,7}[a-z])
(?=.{1,7}[A-Z])
each time, it looks for the target (eg the first digit) but allows 1 to 7 occurances of any character before it.
Then it will match 8 to 13 alphanumeric characters.
NOTE to Powershell users:
Use a search group to be able to extract a result
$password = [regex]::match($string-to-search,'(?=.{1,7}\d)(?=.{1,7}[a-z])(?=.{1,7}[A-Z])([a-zA-Z\d]{8,13})').Groups[1].Value
I'm validating some input fields. Here's the regex for a simple example:
^\[0-9]\{6,6}\$
In the example, it requires 6 numbers to be input. However, I want to relax the validation a little and allow spaces where necessary, and remove them later - an example might be a bank sort code.
In the UK, a sort code could be written as 123456, or perhaps 12 34 56.
I know I can amend the expression to include a space within the brackets and relax the numbers in the curly brackets, but what I'd like to do is continue to limit the digits so that 6 must always be input, and allow none or more spaces - of course the spaces could be anywhere.
I'm not sure how to approach this - any ideas, help appreciated.
Try this:
^(\d\s*){6}$
It allows 0 or more whitespace characters after every digit.
If you want to limit whitespace to be inside the digits (without leading or trailing spaces):
^(\d\s*){5}\d$
If you allow spaces at any position alongside 6 digits, then you need
^(\s*[0-9]){6}\s*$
See regex demo
The \s* matches any whitespace, 0 or more repetitions.
Note that a limiting quantifier {6,6} (minimum 6 and maximum 6 repetitions) is equal to {6}.
Also, note that you need to double escape the \s as \\s if you pass the regex pattern as a regular string literal.
And if you plan to only allow regular spaces, not all whitespace, just use
^([ ]*[0-9]){6}[ ]*$
I think you want to look at a lookahead expression
This site explains them in more detail
For your example, ^(?=(\s*[0-9]\s*){6})(\d*\s*)$
This looks for any amount of space, followed by a digit followed by any amount of space 6 times.
Other answers I've seen so far only allow a total of 6 characters, this expression will allow any number of spaces but only 6 digits, no more, no less.
Note: ^(\s*[0-9]\s*){6}$ this will also work, without the lookahead expression
JavaScript Example
I am trying to write a regex to max a sequence of numbers that is 5 digits long or over, but I ignore any spaces, dashes, parens, or hashes when doing that analysis. Here's what I have so far.
(\d|\(|\)|\s|#|-){5,}
The problem with this is that this will match any sequence of 5 characters including those characters I want to ignore, so something like "#123 " would match. While I do want to ignore the # and space character, I still need the number itself to be 5 digits or more in order to qualify at a match.
To be clear, these would match:
1-2-3-4-5
123 45
2(134) 5
Bonus points if the matching begins and ends with a number rather than with one of those "special characters" I am excluding.
Any tips for doing this kind of matching?
If I understood requirements right you can use:
^\d(?:[()\s#-]*\d){4,}$
RegEx Demo
It always matches a digit at start. Then it is followed by 4 or more of a non-capturing group i.e. (?:[()\s#-]*\d) which means 0 or more of any listed special character followed by a digit.
So just repeat a digit, followed by any other sequence of allowed characters 5 or more times:
^(\d[()\s#-]*){5,}$
You can ensure it ends on a digit if you subtract one of the repetitions and add an explicit digit at the end:
^(\d[()\s#-]*){4,}\d$
You can suggest non-digits with \D so et would be something like:
(\d\D*){5,}
Here is a guide.
Can I use
\d\d\d\d[^\d]
to check for four consecutive numbers?
For example,
411112 OK
455553 OK
1200003 OK
f44443 OK
g55553 OK
3333 OK
f4442 No
45553 No
f4444g4444 No
f44444444 No
If you want to find any series of 4 digits in a string /\d\d\d\d/ or /\d{4}/ will do. If you want to find a series of exactly 4 digits, use /[^\d]\d{4}[^\d]/. If the string should simply contain 4 consecutive digits use /^\d{4}$/.
Edit: I think you want to find 4 of the same digits, you need a backreference for that. /(\d)\1{3}/ is probably what you're looking for.
Edit 2: /(^|(.)(?!\2))(\d)\3{3}(?!\3)/ will only match strings with exactly 4 of the same consecutive digits.
The first group matches the start of the string or any character. Then there's a negative look-ahead that uses the first group to ensure that the following characters don't match the first character, if any. The third group matches any digit, which is then repeated 3 times with a backreference to group 3. Finally there's a look-ahead that ensures that the following character doesn't match the series of consecutive digits.
This sort of stuff is difficult to do in javascript because you don't have things like forward references and look-behind.
Should the numbers be part of a string, or do you want only the four numbers. In the later case, the regexp should be ^\d{4}$. The ^ marks the beginning of the string, $ the end. That makes sure, that only four numbers are valid, and nothing before or after that.
That should match four digits (\d\d\d\d) followed by a non digit character ([^\d]). If you just want to match any four digits, you should used \d\d\d\d or \d{4}. If you want to make sure that the string contains just four consecutive digits, use ^\d{4}$. The ^ will instruct the regex engine to start matching at the beginning of the string while the $ will instruct the regex engine to stop matching at the end of the string.