I'm writing a simple code in java/android.
I want to create regex that matches:
0
123
123,1
123,44
and slice everything after second digit after comma.
My first idea is to do something like that:
^\d+(?(?=\,{1}$)|\,\d{1,2})
^ - from begin
\d+ match all digits
?=\,{1}$ and if you get comma at the end
do nothin
else grab two more digits after comma
but it doesn't match numbers without comma; and I don't understand what is wrong with the regex.
You may use
^(\d+(?:,\d{1,2})?).*
and replace with $1. See the regex demo.
Details:
^ - start of string
-(\d+(?:,\d{1,2})?) - Capturing group 1 matching:
\d+ - one or more digits
(?:,\d{1,2})? - an optional sequence of:
, - a comma
\d{1,2} - 1 or 2 digits
.* - the rest of the line that is matched and not captured, and thus will be removed.
basic regex : [0-9]+[, ]*[0-9]+
In case you want to specify min max length use:
[0-9]{1,3}[, ]*[0-9]{0,2}
Here:
,{1}
says: exactly ONE ","
Try:
,{0,1}
for example.
Related
I created regex expression in JAVA for 2 links at once:
https://downloads.test.test.testagain.tes/test-test/test/te25st24w/te43s5t25x/0twt42ts/test0218.pdf
https://downloads.test.test.testagain.tes/test-test/test/te25st24w/te43s5t25x/0twt42ts/TestTes-09-05-2018.pdf
Regex:
String REGEX_LINK = "https:..downloads.test.test.testagain.tes.test-test.test."
Pattern pattern = Pattern.compile( REGEX_LINK + ".[\w*/]*.((\d{2}-\d{2}-)?\d{4}).pdf" );
But I have to create regex expression for 3 links at once and I don't know how to do that, I need help with this:
https://downloads.test.test.testagain.tes/test-test/test/te25st24w/te43s5t25x/0twt42ts/test0218.pdf
https://downloads.test.test.testagain.tes/test-test/test/te25st24w/te43s5t25x/0twt42ts/TestTes-09-05-2018.pdf
https://downloads.test.test.testagain.tes/test-test/test/te25st24w/te43s5t25x/0twt42ts/01-01-18_Testt_Testing_ASB_Test_Final.pdf
I have to create one regex expression to extract String from 1 link: "0218", from 2 link: "09-05-2018", from 3 link: "01-01-18"
Maybe someone has a any idea how to do this?
You could match 2 times 2 digits with an optional hyphen, and then optionally 4 or 2 digits preceded by a hyphen.
Note that the pattern by itself does not verify a valid date.
(?<!\d)(\d{2}-?\d{2}(?:-(?:\d{4}|\d{2}))?)\S*\.pdf\b
Explanation
(?<!\d) Negative lookbehind, assert not a digit to the left
( Capture group 1
\d{2}-?\d{2} Match 2 digits, optional hyphen and 2 digits
(?:-(?:\d{4}|\d{2}))? Optionally match - and either 4 or 2 digits
) Close group 1
\S* Match optional non whitespace chars
\.pdf\b Match a dot and pdf followed by a word boundary
Regex demo
Or if there can not be any other digits following till the end of the string:
(?<!\d)(\d{2}-?\d{2}(?:-(?:\d{4}|\d{2}))?)[^\d\s]*\.pdf\b
Regex demo
I have this String and I want to filter the digit that came after the big number with the space, so in this case I want to filter out 2 and 0.32. I used this regex below which only filters out decimal numbers, however I want to filter both decimals and integer numbers, is there any way?
String s = "ABB123,ABPP,ADFG0/AA/BHJ.S,392483492389 2,BBBB,YUIO,BUYGH/AA/BHJ.S,3232489880 0.32"
regex = .AA/BHJ.S,\d+ (\d+.?\d+)
https://regex101.com/r/ZqHDQ8/1
The problem is that \d+.?\d+ matches at least two digits. \d+ matches one or more digits, then .? matches any optional char other than line break char, and then again \d+ matches (requires) at least one digit (it matches one or more).
Also, note that all literal dots must be escaped.
You can use
.AA/BHJ\.S,\d+\s+(\d+(?:\.\d+)?)
See the regex demo.
Details:
. - any one char
AA/BHJ\.S, - a AA/BHJ.S, string
\d+ - one or more digits
\s+ - one or more whitespaces
(\d+(?:\.\d+)?) - Group 1: one or more digits, and then an optional sequence of a dot and one or more digits.
You could look for anything following /AA/BHJ with a reluctant quantifier, then use a capturing group to look for either digits or one or more digits followed by a decimal separator and other digits.
/AA/BHJ.*?\s+(\d+\.\d+|\d+)
Here is a link to test the regex:
https://regex101.com/r/l5nMrD/1
This question already has an answer here:
Reference - What does this regex mean?
(1 answer)
Closed 3 years ago.
Can someone help me with the following Java regex expression? I've done some research but I'm having a hard time putting everything together.
The regex:
"^-?\\d+$"
My understandning of what each symbol does:
" = matches the beginning of the line
- = indicates a range
? = does not occur or occurs once
\\d = matches the digits
+ = matches one or more of the previous thing.
$ = matches end of the line
Is the regex saying it only want matches that start or end with digits? But where do - and ? come in?
- only indicates a range if it's within a character class (i.e. square brackets []). Otherwise, it's a normal character like any other. With that in mind, this regex matches the following examples:
"-2"
"3"
"-700"
"436"
That is, a positive or negative integer: at least one digit, optionally preceded by a minus sign.
Some regex is composed, as you have now, the correct way to read your regex is :
^ start of word
-? optional minus character
\\d+ one or more digits
$ end of word
This regex match any positive or negative numbers, like 0, -15, 558, -19663, ...
Fore details check this good post Reference - What does this regex mean?
"^-?\\d+$" is not a regex, it's a Java string literal.
Once the compiler has parsed the string literal, the string value is ^-?\d+$, which is a regex matching like this:
^ Matches beginning of input
- Matches a minus sign
? Makes previous match (minus sign) optional
\d Matches a digit (0-9)
+ Makes previous match (digit) match repeatedly (1 or more times)
$ Matches end of input
All-in-all, the regex matches a positive or negative integer number of unlimited length.
Note: A - only denotes a range when inside a [] character class, e.g. [4-7] is the range of characters between '4' and '7', while [3-] and [-3] are not ranges since the start/end value is missing, so they both just match a 3 or - character.
I cant build the right regex.
Valid:
1.1.1
1.1-1
1-1.1
1-1-1
1-1
1.1
Invalid:
1..1
1.
1--1
1-
so far i got
^[0-9]+[0-9.-][0-9]+$
thanks for your help
The ^[0-9]+[0-9.-][0-9]+$ pattern matches a string that fully matches the pattern: 1 or more digits ([0-9]+), a digit or . or - ([0-9.-]) and then 1 or more digits ([0-9]+). It can match consecutive - or/and . inside a string of digits.
You may use
^[0-9]+(?:[.-][0-9]+)*$
See the regex demo
If you use it in the .matches() method, the ^ and $ anchors can be omitted.
Details:
^ - start of string
[0-9]+ - 1 or more (the + quantifier matches 1 or more occurrences, if you only need to match a single occurrence remove the + quantifier) digits
(?:[.-][0-9]+)* - zero or more consecutive sequences of
[.-] - a . or -
[0-9]+ - 1 or more digits (the same quantifier note as above applies)
$ - end of string.
This here should do:
^[0-9]([.-][0-9])*$
One digit, followed by zero or more occurrences of (dot/minus digit)
Slight variation on other answers.
You did not indicate the case of a lone digit without period and hyphen:
(invalid)
1- (invalid)
1 (I have assumed this case is invalid)
Also this regex only allows single digits (e.g. 2.2.2, not 22.22.22)
^\d([.-]\d)+$
Both
^[0-9]([.-][0-9])*$
and
^[0-9]+(?:[.-][0-9]+)*$
works. Thanks
Maybe this is asked somewhere but certainly I couldn't find the answer I want so:
I'm having difficulties to match specific characters in a string:
"88551554,86546546,51516565"
The digits I want to match are the X's in the following :
"XXXXX554,XXXXX546,XXXXX565"
Right now I'm only able to find out the last 3 digits before each comma :
\d{3}(?=,)
And since the length of the numbers are dynamic, it seems not possible to specify the number of digits before the 3 digits.
Anyone can help?
Thanks in advance!
You can use this lookahead regex:
(\d+)(?=\d{3}(?:,|$))
RegEx Demo
This will match and group 1 or more digits that must be followed by 3 digits and a comma or end of input. Check MATCH INFORMATION in the demo link for captured groups.
Update: To replace all those matched digits by X use:
str = str.replaceAll("\\d(?=\\d*\\d{3}(?:,|$))", "X");
RegEx Demo2
To match it use:
\d+(?=\d{3})
This regex does:
\d+... Match a digit (0-9) between one and unlimmited times.
(?=\d{3}) ... Match a digit (0-9) exactly three times inside an positive lookahead.