so this is going to be a regex for email address.
username: capital and small letters, digits, and underscore and dot
^[A-Za-z0-9._]+
then there's # and domain: capital and small letters and digits
#[A-Za-z0-9]+
then there's dot and tld: at least 2 characters (letters and digits) and can have maximum one dot.
I used | to have both at least 2 characters and maximum one dot:
([A-Za-z0-9]{2,}|[.]{0,1})
so the complete regex is this:
regex reg ("^[A-Za-z0-9._]+#[A-Za-z0-9]+\\.([A-Za-z0-9]{2,}|[.]{0,1})$");
but the maximum one dot rule isn't working. when I input zohal#gmail.df.g (not real of course) it gives false. it does work in other cases like zohal#gmail.com though.
You may use
regex reg(R"(^[A-Za-z0-9._]+#[A-Za-z0-9]+(?:\.[A-Za-z0-9]+)+$)")
See the regex demo
Details
^ - start of string
[A-Za-z0-9._]+ - 1 or more letters, digits, . or _
# - a # char
[A-Za-z0-9]+ - 1 or more letters or digits
(?:\.[A-Za-z0-9]+)+ - 1 or more occurrences of a dot and then 1 or more letters or digits
$ - an end of string position.
Since there are two + quantified patterns after #, you do not need an explicit (?=(?:[^A-Za-z0-9]*[A-Za-z0-9]){2}) lookahead to require at least two letters or digits.
Related
I want to find invoice numbers with a regex. The string has be longer than 3 char. It may contain signs like {., , /, _}, all numbers and it may contain one or two capital letters - those can stay alone or after each other. That is, what I'm currently trying, without success.
`([0-9-\.\\\/_]{,3})([A-Z]{0,2})?`
Here I have two examples, which should be matched:
019S836/03717008
DR094255
This should not be matched:
DRF094255
Can somebody help me please?
You can use
^(?!(?:[^A-Z]*[A-Z]){3})(?=\D*\d)[0-9A-Z.\\\/_-]{3,}$
See the regex demo.
Details:
^ - start of string
(?!(?:[^A-Z]*[A-Z]){3}) - a negative lookahead that fails the match if, immediately to the right of the current location (i.e. from the start of string), there are three occurrences of any zero or more chars other than uppercase ASCII letters followed with one uppercase ASCII letter
(?=\D*\d) - there must be at least one digit in the string
[0-9A-Z.\\\/_-]{4,} - four or more occurrences of digits, uppercase letters, ., \, /, _ or -
$ - end of string.
I am trying to block any strings that contain more than 3 numbers and prevent special characters. I have the special characters part down. I'm just missing the number part.
For example:
"Hello 1234" - Not Allowed
"Hello 123" - Allowed
I've tried the following:
/^[!?., A-Za-z0-9]+$/
/((^[!?., A-Za-z]\d)([0-9]{3}+$))/
/^((\d){2}[a-zA-Z0-9,.!? ])*$/
The last one is the closest I got as it prevents any special characters and any numbers from being entered at all.
I've looked through previous posts, but am coming up short.
Edit for clarification
Essentially I'm trying to find a way to prevent customers from entering PII on a form. No submission should be allowed that contains more than 3 numbers in a string.
Hello1234 - Not allowed
12345 - Not allowed
1111 - not allowed
No where in the comment section when the user enters the string should there be more than 3 numbers in total.
About the patterns that you tried
^[!?., A-Za-z0-9]+$ The pattern matches 1+ times any of the listed, including 1 or more digits
((^[!?., A-Za-z]\d)([0-9]{3}+$)) If {3}+ is supported, the pattern matches a single char from the character class, 1 digit followed by 3 digits
^((\d){2}[a-zA-Z0-9,.!? ])*$ The pattern repeats 0+ times matching 2 digits and 1 of the listed in the character class
You can use a negative lookahead if that is supported to assert not 4 digits in a row.
^(?!.*\d{4})[a-zA-Z0-9,.!? ]+$
regex demo
If there can not be 4 digits in total, but 0-3 occurrences:
^[a-zA-Z,.!? ]*(?:\d[a-zA-Z,.!? ]*){0,3}$
Explanation
^ Start of string
[a-zA-Z,.!? ]* Match 0+ times any of the listed (without a digit)
(?:\d[a-zA-Z,.!? ]*){0,3} Repeat 0 - 3 times matching a single digit followed by optional listed chars (Again without a digit)
$ End of string
regex demo
If you don't want to match an empty string and a lookahead is supported:
^(?!$)[a-zA-Z,.!? ]*(?:\d[a-zA-Z,.!? ]*){0,3}$
See another regex demo
Here is my two cents:
^(?!(.*\d){4})[A-Za-z ,.!?\d]+$
See the online demo
^ - Start string anchor.
(?! - Open a negative lookahead.
( - Open capture group.
.*\d - Match anything other than newline up to a digit.
){4} - Close capture group and match it 4 times.
) - Close negative lookahead.
[A-Za-z ,.!?\d]+ - 1+ Characters from specified class.
$ - End string anchor.
I think it should cover what you described.
Assuming you mean <= 3 digits, this may be a naive one but how about
[ALLOWED_CHARS]*[0-9]?[ALLOWED_CHARS]*[0-9]?[ALLOWED_CHARS]*[0-9][ALLOWED_CHARS]*?
Fill [ALLOWED_CHARS] to whatever you define is not special character and nums.
lets say i have String which starts with two letters and letters are followed with underscore and numbers
XX_333-335 [A-Za-z]{2}_\d{3}-\d{3}`
` - this works good for me
but string can be: (this works as well)
XX_333-335;338;340-341 -^[A-Za-z]{2}_\d{3}-\d{3};|\d{3}|\d{3}-\d{3}
but how to check with regex if number length is 3 places?
XX_0333-0335;0338;340-0341 - In this example there should be no matches, because numbers have four positions not three
Is there any way how to solve it with regex?
thank you
You can use
^[A-Za-z]{2}_\d{3}(?:-\d{3})?(?:;\s*\d{3}(?:-\d{3})?)*$
See the regex demo
Details
^ - start of string
[A-Za-z]{2} - two ASCII letters
_ - an underscore
\d{3} - three digits
(?:-\d{3})? - an optional occurrence of - and three digits
(?:;\s*\d{3}(?:-\d{3})?)* - zero or more occurrences of a semi-colon followed with 0+ whitespaces, three digits and an optional sequence of three digits
$ - end of string.
This would do it:
^[A-Za-z]{2}_(?:\d{3}(?:[; -]+|$))+$
https://regex101.com/r/4ULAql/1
I've run into some issues with this one and cannot find it in past questions.
Criteria:
Reject pure digits
Reject pure letters
Reject any symbols
Accept ONLY Alphanumeric combo
MUST be equal to 10 characters total
Here is what I have made and the problems with each:
^(?!^\d*$)[a-zA-Z\d]{10}$
This fails criteria #2
^[a-zA-Z0-9]{10}$
This fails criteria #1
I have tried some others that meet all criteria but fail the 10 char limit.
Any help is appreciated.
You may use a second lookahead:
^(?!\d+$)(?![a-zA-Z]+$)[a-zA-Z\d]{10}$
See the regex demo and the Regulex graph:
Details
^ - start of string
(?!\d+$) - a negative lookahead that makes sure the whole string is not composed of just digits
(?![a-zA-Z]+$) - the whole string cannot be all letters
[a-zA-Z\d]{10} - 10 letters or digits
$ - end of string.
Try this:
(?=^.{10}$)^([a-z]+\d[a-z0-9]*|\d+[a-z][a-z0-9]*)$
Demo
Explanation:
(?=^.{10}$)^([a-z]+\d[a-z0-9]*|\d+[a-z][a-z0-9]*)$
(?=^.{10}$) # there's exactly 10 characters following
^( | )$ # we match the entire string, containing either:
[a-z]+\d[a-z0-9]* # letters, followed by a number, followed by alphanumerics, or
\d+[a-z][a-z0-9]* # numbers, followed by a letter, followed by alphanumerics
Use lookahead to find at least one char of each type you require, and specify the length and char limitation in the "regular" part of your regex:
^(?=.*[a-zA-Z])(?=.*\d)[0-9a-zA-Z]{10}$
(?=.*[a-zA-Z])- Look ahead and find a letter,
(?=.*\d) - Look ahead and find a digit
[0-9a-zA-Z]{10} - exactly 10 digit/letter chars
I need regex that only allows a maximum of 2 digits (or whatever the desired limit is actually) to be entered into an input field.
The requirements for the field are as follows:
Allow a-z A-Z
Allow 0-9
Allow - and . characters
Allow spaces (\s)
Do not allow more than 2 digits
Do not allow any other special characters
I have managed to put together the following regex based on several answers on SO:
^(?:([a-zA-z\d\s\.\-])(?!([a-zA-Z]*\d.*){3}))*$
The above regex is really close. It works successfully for the following:
test 12 test
test12
test-test.12
But it allows an input of:
123 (but not 1234, so it's close).
It only needs to allow an input of 12 when only digits are entered into the field.
I would like some help in finding a more efficient and cleaner (if possible) solution than my current regex - but it must still be regex, no JS.
You could use a positive lookahead like
(?=^(?:\D*\d\D*){2}$) # only two digits
^[- .\w]+$ # allowed characters
See a demo on regex101.com.
You may use a negative lookahead anchored at the start that will make the match fail once there are 3 digits found anywhere in the string:
^(?!(?:[^0-9]*[0-9]){3})[a-zA-Z0-9\s.-]*$
^^^^^^^^^^^^^^^^^^^^^^^
See the regex demo
Details:
^ - start of string
(?!(?:[^0-9]*[0-9]){3}) - the negative lookahead failing the match if exactly 3 following sequences are found:
[^0-9]* - zero or more chars other than digits
[0-9] - a digit (thus, the digits do not have to be adjoining)
[a-zA-Z0-9\s.-]* - 0+ ASCII letters, digits, whitespace, . or - symbols
$ - end of string.