This question already has answers here:
Regular expression for floating point numbers
(20 answers)
Closed 3 years ago.
I am trying to extract rating from a tweet using regular expression. For example for below tweet, I want to get the user rating(9.75) and maximum rating(10).
This is Logan, the Chow who lived. He solemnly swears he's up to lots of good. 9.75/10
I used below regex, but the capture groups 1 and 2 has results 75 and 10. I am not sure why the user rating is captured only after decimal group.
.*(\d+\.?\d+)\/(\d*\.?\d*)
If you want both numbers to have optional decimal you should place the match one or ore + and the match zero or more * on the correct places, where they match the mandatory leading digit and then the optional decimals
(\d+\.?\d+)\/(\d*\.?\d*)
with
(\d+\.?\d*)\/(\d+\.?\d*)
This will match at least one digit followed by maybe a dot and then again maybe some more digits.
Live link: https://regex101.com/r/qc5Zwz/1
\b(\d+(?:\.\d+)?)\/(\d+)\b
\b - expect a word boundary (eg, space, non-letter character)
( - start capturing the 'rating'
\d+ - integer part
(?:\.\d+)? - wrap the decimal part, don’t capture it as a group; make it optional
) - end of 'rating' capturing group
\/- expect a forward slash
(\d+) - capture the 'maximum'
\b - expect a word boundary again
const text = 'This is Logan, the Chow who lived. He solemnly swears he\'s up to lots of good. 9.75/10'
const pattern = /\b(\d+(?:\.\d+)?)\/(\d+)\b/
console.log(text.match(pattern))
https://regex101.com/r/foO1DF/2
Related
This question already has answers here:
Regex for matching season and episode
(5 answers)
Closed 7 months ago.
I would like to create a regex expression that matches all possible episode numbering formats from a tv show file format.
I currently have this regex which matches most but not all of the list of examples.
(?:(?<=e)|(?<=episode)|(?<=episode[\.\s]))(\d{1,2})|((?<=-)\d{1,2})
The one it does not match is when there are two episodes directly after another e0102 should match 01 and 02.
You can find the regex example with test cases here
As per your comment, I went by following assumptions:
Episode numbers are never more than three digits long;
Episode strings will therefor have either 1-3 digits or 4 or 6 when its meant to be a range of episodes;
There is never an integer of 5 digits assuming the same padding would be used for both numbers in a range of episodes;
This would mean that lenght of either 4 or 6 digits needs to be split evenly.
Therefor, try the following:
e(?:pisode)?\s*(\d{1,3}(?!\d)|\d\d\d??)(?:-?e?(\d{1,3}))?(?!\d)
Here is an online demo. You'll notice I added some more samples to showecase the above assumptions.
e(?:pisode)?\s* - Match either 'e' or 'episode' with 0+ trailing whitespace characters;
(\d{1,3}(?!\d)|\d\d\d??) - A 1st capture group to catch 1-3 digits if not followed by any other digit or two digits;
(?:-?e?(\d{1,3}))? - An optional non-capture group with a nested 2nd capture group looking for optional hyphen and literal 'e' with trailing digits (1-3);
(?!\d) - There is no trailing digit left.
I am struggling to write the RegEx for the following criteria:
The number can be positive / negative
Optional - at the start
Between 1 and 5 numbers before the decimal point
2 decimal places only (optional)
Stop user from typing more than 1 . or -
This is the regex I have tried to implement which does not work for me.
^((-?[0-9]{1,5}(\.?){1,1}[0-9]{0,2})
It should allow the user to type out the following numbers.
-1.12
12345
1
123
12.12
Any help would be appreciated!
You may use
^-?\d{0,5}(?:(?<=\d)\.\d{0,2})?$
See the regex demo.
Details
^ - start of string
-? - an optional -
\d{0,5} - zero to five digits
(?:(?<=\d)\.\d{0,2})? - an optional sequence of
(?<=\d) - there must be a digit immediately to the left of the current location
\. - a dot
\d{0,2} - zero, one or two digits
$ - end of string.
If you want to validate while typing, you could make use of optional groups to accept intermediate values and do a final check on the whole pattern when processing the value.
^-?(?:\d{1,5}(?:\.\d{0,2})?)?$
Explanation
^ Start of string
-? Optional hyphen
(?: Non capture group
\d{1,5} Match 1-45 digits
(?: Non capture group
\.\d{0,2} Match a dot and 0-2 digits
)? Close group and make it optional
)? Close group and make it optional
$ End of string
Regex demo
To validate the final pattern, you could match an optional -, 1-5 digits and an optional decimal part:
^-?\d{1,5}(?:\.\d{1,2})?$
Regex demo
The regex ^(-?(\d{1,5}(\.\d{0,2})?)?)$ should work if you want to match strings that end in . such as 123. demo of this regex
Otherwise, change the 0 to a 1 as follows: ^(-?(\d{1,5}(\.\d{1,2})?)?)$. Then it will only match strings that have a digit after the decimal point.
The regex that you posted allows strings with more than 2 digits after the decimal point because it stops matching after the 2 digits, even if the string continues. Adding a $ at the end of the regex stops it from matching strings that continue after the part we want.
This regex ^(-?\d{1,5}(\.\d{0,2})?)$ will validate the input once the user has finished typing, because I assume that you don't want -to be valid at that point.
This question already has an answer here:
Reference - What does this regex mean?
(1 answer)
Closed 3 years ago.
I need a regular expression to validate strings with the prefix 'CON' followed by an optional space followed by 8 digits.
I've tried various expressions, I got tangled up and now I'm lost.
^(CON+s\?d{8})$
\bCON\b\S?D{8}
Syntax is off a bit
^(CON\s?\d{8})
( starts a capturing group
CON is exactly matched
\s matches any white space character and the ? makes it optional
\d{8} matches 8 digits
) ends the capturing group
You were pretty well off to start, Hope this helps :)
keeping in mind If there is no space, then there shouldn't be 8 more digits
^CON(\ \d{8})?
If the string you are looking for can be part of a larger string (note that in this case it may be preceded or followed by anything, even other digits):
CON\s?\d{8}
If the string must match in full, use ^$ to designate that:
^CON\s?\d{8}$
You can add variations to it, if say you want it to begin/end with a word boundary - use \bto indicate that. If you want it to end in a non-digit, use \D+ at the end, instead of $.
Finally, if you want the string to end with an EOL or a non-digit, you may use an expression like this:
CON\s?\d{8}(\D+|$) or the same with a non-capturing group: CON\s?\d{8}(?:\D+|$)
I am looking for help here. I want to write a regex to help me find EXACTLY a 7 digit in string - no more or less.
For instance in this string:
1234567 RE:TKT-2744870-R6P1G0: Gentle Reminder
It should return only 1234567
In this one:
12345678 RE:TKT-2744870-R6P1G0: Gentle Reminder
It should return none.
Can you help me with this one.
thanks in advance.
The proper regex should include \d{7} (7 digits) and 2 "border criteria",
for both start and end of the match, to block matching of a fragment
from longer sequence of digits.
My first thought was that neither before nor after the match there can be any digit.
But as I see from your example, these border criteria should be extended.
The set of "forbidden" chars (either before or after the match) should
include also - and letters.
E.g. 2744870 in your example data contains just 7 digits (no more, no less),
but you still don't want it to be matched, apparently because they are surrounded with - chars.
To keep the regex short, I propose:
(?<![\w-])\d{7}(?![\w-])
Details:
(?<![\w-]) - Negative lookbehind for word char or -.
\d{7} - 7 digits.
(?![\w-]) - Negative lookahead for word char or -.
If you decide to extend the set of "forbidden" chars in both border criteria,
just add them to [...] fragments in lookbehind / lookahead (but - char
should remain at the end, otherwise it must be quoted with \).
Regex like (\d{7})[^\d] (in other proposition) is wrong,
as it matches last 7 digits from any longer sequence of digits
(no "front border criterion").
It matches also both 2744870 (surronded with - chars), which are not
to be matched.
This one should do for your examples:
(\d{7})[^\d]
The first matching group contains the seven digits.
Alternatively –as suggested in the comments– you can use a negative lookahead to only match the seven digits and not require matching groups:
^\d{7}(?!\d)
I would like to check if a phone number contains exactly 3 digits - dot - 3 digits - dot - 3 digits. (e.g. 123.456.789)
So far I have this, but it doesn't work:
^(\d{3}\){2}\d{4}$
Note that an escaped bracket \) loses its special meaning in regex and the pattern becomes invalid since the capturing group is not closed.
If you want to match a dot with a regex, you need to include it to your pattern, and if you say 3 digits must be at the end there is no point in declaring 4 digits with \d{4}.
^(\d{3}\.){2}\d{3}$
^ ^
or if we expand the first group:
^\d{3}\.\d{3}\.\d{3}$
So all the fix consists in adding a dot after the second backslash and adjusting the final limiting quantifier.
Note that for mostly "stylistics" concerns (since efficiency gain is insignificant) I'd use a non-capturing group with the first regex variant:
^(?:\d{3}\.){2}\d{3}$