Trying to matchAll a regex on a JavaScript string - javascript

I'm trying to string.matchAll the following string:
const text = 'textA [aaa](bbb) textB [ccc](ddd) textC'
I want to match the following:
1st: "textA [aaa](bbb)"
2nd: " textB [ccc](ddd)"
3rd: " textC"
NOTE: The capturing groups are already present in the regex. That's what I need.
It's almost working, but so far I couldn't think of a way to match the last part of the string, which is just " textC", and doesn't have the [*](*) pattern.
What am I doing wrong?
const text = 'textA [aaa](bbb) textB [ccc](ddd) textC'
const regexp = /(.*?)\[(.+?)\]\((.+?)\)/g;
const array = Array.from(text.matchAll(regexp));
console.log(JSON.stringify(array[0][0]));
console.log(JSON.stringify(array[1][0]));
console.log(JSON.stringify(array[2][0]));
UPDATE:
Besides the good solutions provided in the answers below, this is also an option:
const text= 'textA [aaa](bbb) textB [ccc](ddd) textC'
const regexp = /(?!$)([^[]*)(?:\[(.*?)\]\((.*?)\))?/gm;
const array = Array.from(text.matchAll(regexp));
console.log(array);

It's because there is no third match. After the first two matches, the only thing left in the string is "text C":
https://regex101.com/r/H9Kn0G/1/
to fix this, make the whole second part optional (also note the initial \w instead of . to prevent that dot from eating the whole string, as well as the "grouping only" parens used to surround the optional part, which keeps your match groups the same):
(\w+)(?:\s\[(.+?)\]\((.+?)\))?
https://regex101.com/r/Smo1y1/2/

Solution 1: Splitting through matching
You may split by matching the pattern and getting substrings from the previous index up to the end of the match:
const text = 'textA [aaa](bbb) textB [ccc](ddd) textC'
const regexp = /\[[^\][]*\]\([^()]*\)/g;
let m, idx = 0, result=[];
while(m=regexp.exec(text)) {
result.push(text.substring(idx, m.index + m[0].length).trim());
idx = m.index + m[0].length;
}
if (idx < text.length) {
result.push(text.substring(idx, text.length).trim())
}
console.log(result);
Note:
\[[^\][]*\]\([^()]*\) matches [, any 0+ chars other than [ and ] (with [^\][]*), then ](, then 0+ chars other than ( and ) (with [^()]*) and then a ) (see the regex demo)
The capturing groups are removed, but you may restore them and save in the resulting array separately (or in another array) if needed
.trim() is added to get rid of the leading/trailing whitespace (remove if not necessary).
Solution 2: Matching optional pattern
The idea is to match any chars before the pattern you have and then match either your pattern or end of string:
let result = text.match(/(?!$)(.*?)(?:\[(.*?)\]\((.*?)\)|$)/g);
If the string can have line breaks, replace . with [\s\S], or consider this pattern:
let result = text.match(/(?!$)([\s\S]*?)(?:\[([^\][]*)\]\(([^()]*)\)|$)/g);
See the regex demo.
JS demo:
const text = 'textA [aaa](bbb) textB [ccc](ddd) textC'
const regexp = /(?!$)(.*?)(?:\[(.*?)\]\((.*?)\)|$)/g;
const array = Array.from(text.matchAll(regexp));
console.log(JSON.stringify(array[0][0]));
console.log(JSON.stringify(array[1][0]));
console.log(JSON.stringify(array[2][0]));
Regex details
(?!$) - not at the end of string
(.*?) - Group 1: any 0+ chars other than line break chars as few as possible (change to [\s\S]*? if there can be line breaks or add s modifier since you target ECMAScript 2018)
(?:\[(.*?)\]\((.*?)\)|$) - either of the two alternatives:
\[(.*?)\]\((.*?)\) - [, Group 2: any 0+ chars other than line break chars as few as possible, ](, Group 3: any 0+ chars other than line break chars as few as possible, and a )
| - or
$ - end of string.

That is what I've ended up using:
const text= 'textA [aaa](bbb) textB [ccc](ddd) textC'
const regexp = /(?!$)([^[]*)(?:\[(.*?)\]\((.*?)\))?/gm;
const array = Array.from(text.matchAll(regexp));
console.log(array);

Related

How do I replace the last character of the selected regex?

I want this string {Rotation:[45f,90f],lvl:10s} to turn into {Rotation:[45,90],lvl:10}.
I've tried this:
const bar = `{Rotation:[45f,90f],lvl:10s}`
const regex = /(\d)\w+/g
console.log(bar.replace(regex, '$&'.substring(0, -1)))
I've also tried to just select the letter at the end using $ but I can't seem to get it right.
You can use
bar.replace(/(\d+)[a-z]\b/gi, '$1')
See the regex demo.
Here,
(\d+) - captures one or more digits into Group 1
[a-z] - matches any letter
\b - at the word boundary, ie. at the end of the word
gi - all occurrences, case insensitive
The replacement is Group 1 value, $1.
See the JavaScript demo:
const bar = `{Rotation:[45f,90f],lvl:10s}`
const regex = /(\d+)[a-z]\b/gi
console.log(bar.replace(regex, '$1'))
Check this out :
const str = `{Rotation:[45f,90f],lvl:10s}`.split('');
const x = str.splice(str.length - 2, 1)
console.log(str.join(''));
You can use positive lookahead to match the closing brace, but not capture it. Then the single character can be replaced with a blank string.
const bar= '{Rotation:[45f,90f],lvl:10s}'
const regex = /.(?=})/g
console.log(bar.replace(regex, ''))
{Rotation:[45f,90f],lvl:10}
The following regex will match each group of one or more digits followed by f or s.
$1 represents the contents captured by the capture group (\d).
const bar = `{Rotation:[45f,90f],lvl:10s}`
const regex = /(\d+)[fs]/g
console.log(bar.replace(regex, '$1'))

Regex match apostrophe inside, but not around words, inside a character set

I'm counting how many times different words appear in a text using Regular Expressions in JavaScript. My problem is when I have quoted words: 'word' should be counted simply as word (without the quotes, otherwise they'll behave as two different words), while it's should be counted as a whole word.
(?<=\w)(')(?=\w)
This regex can identify apostrophes inside, but not around words. Problem is, I can't use it inside a character set such as [\w]+.
(?<=\w)(')(?=\w)|[\w]+
Will count it's a 'miracle' of nature as 7 words, instead of 5 (it, ', s becoming 3 different words). Also, the third word should be selected simply as miracle, and not as 'miracle'.
To make things even more complicated, I need to capture diacritics too, so I'm using [A-Za-zÀ-ÖØ-öø-ÿ] instead of \w.
How can I accomplish that?
1) You can simply use /[^\s]+/g regex
const str = `it's a 'miracle' of nature`;
const result = str.match(/[^\s]+/g);
console.log(result.length);
console.log(result);
2) If you are calculating total number of words in a string then you can also use split as:
const str = `it's a 'miracle' of nature`;
const result = str.split(/\s+/);
console.log(result.length);
console.log(result);
3) If you want a word without quote at the starting and at the end then you can do as:
const str = `it's a 'miracle' of nature`;
const result = str.match(/[^\s]+/g).map((s) => {
s = s[0] === "'" ? s.slice(1) : s;
s = s[s.length - 1] === "'" ? s.slice(0, -1) : s;
return s;
});
console.log(result.length);
console.log(result);
You might use an alternation with 2 capture groups, and then check for the values of those groups.
(?<!\S)'(\S+)'(?!\S)|(\S+)
(?<!\S)' Negative lookbehind, assert a whitespace boundary to the left and match '
(\S+) Capture group 1, match 1+ non whitespace chars
'(?!\S) Match ' and assert a whitespace boundary to the right
| Or
(\S+) Capture group 2, match 1+ non whitespace chars
See a regex demo.
const regex = /(?<!\S)'(\S+)'(?!\S)|(\S+)/g;
const s = "it's a 'miracle' of nature";
Array.from(s.matchAll(regex), m => {
if (m[1]) console.log(m[1])
if (m[2]) console.log(m[2])
});

Multiple OR conditions for words in JavaScript regular expression

I trying to have a regular expression which is finding between two words but those words are not certain one.
2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞASınıfıE10/ENo303
This is my text. I'm trying to find the word between Soyadı and Sınıfı, in this case ERTANĞA, but the word Sınıfı also can be no, numara or any number. This is what I did.
soyad[ıi](.*)S[ıi]n[ıi]f[ıi]|no|numara|[0-9]
[ıi] is for Turkish character issue, don't mind that.
You can use something like below :
/.*Soyad(ı|i)|S(ı|i)n(ı|i)f(ı|i).*|no.*|numera.*|[0-9]/gmi
Here is the link I worked on : https://regex101.com/r/QXLjLF/1
In JS code:
const regex = /.*Soyad(ı|i)|S(ı|i)n(ı|i)f(ı|i).*|no.*|numera.*|[0-9]/gmi;
var str = `2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞASınıfıE10/ENo303`;
var newStr = str.replace(regex, '');
console.log(newStr);
You can use a single capture group to get the word ERTANĞA, keep the character class [ıi] instead of using an alternation for (ı|i) and group the alternatives at the end of the pattern using a non capture group (?:
soyad[ıi](.+?)(?:S[ıi]n[ıi]f[ıi]|n(?:o|umara)|[0-9])
soyad[ıi] Match soyadı or soyadi
(.+?) Capture group 1, match 1 or more chars as least as possible
(?: Non capture group
S[ıi]n[ıi]f[ıi] Match S and then ı or i etc..
| Or
n(?:o|umara) Match either no or numara
| Or
[0-9] Match a digit 0-9
) Close non capture group
Note that you don't need the /m flag as there are no anchors in the pattern.
Regex demo
const regex = /soyad[ıi](.+?)(?:S[ıi]n[ıi]f[ıi]|n(?:o|umara)|[0-9])/gi;
const str = "2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞASınıfıE10/ENo303\n";
console.log(Array.from(str.matchAll(regex), m => m[1]));
This might do it
const str = `2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞASınıfıE10/ENo303
2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞAnumaraE10/ENo303
2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞAnoE10/ENo303`
const re = /(?:Soyad(ı|i))(.*?)(?:S(ı|i)n(ı|i)f(ı|i)|no|numara)/gmi
console.log([...str.matchAll(re)].map(x => x[2]))
ES5
const str = `2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞASınıfıE10/ENo303
2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞAnumaraE10/ENo303
2015ÖĞLEYEMEKKARTI(2016-20.AdıMEVLÜTSoyadıERTANĞAnoE10/ENo303`
const re = /(?:Soyad(ı|i))(.*?)(?:S(ı|i)n(ı|i)f(ı|i)|no|numara)/gmi
const res = []
let match;
while ((match = re.exec(str)) !== null) res.push(match[2])
console.log(res)

Setting the end of the match

I have the following string:
[TITLE|prefix=a] [STORENAME|prefix=b|suffix=c] [DYNAMIC|limit=10|random=0|reverse=0]
And I would like to get the value of the prefix of TITLE, which is a.
I have tried it with (?<=TITLE|)(?<=prefix=).*?(?=]|\|) and that seems to work but that gives me also the prefix of STORENAME (b). So if [TITLE|prefix=a] will be missing in the string, I'll have the wrong value.
So I need to set the end of the match with ] that belongs to [TITLE. Please notice that this string is dynamic. So it could be [TITLE|suffix=x|prefix=y] as well.
const regex = "[TITLE|prefix=a] [STORENAME|prefix=b|suffix=c] [DYNAMIC|limit=10|random=0|reverse=0]".match(/(?<=TITLE|)(?<=prefix=).*?(?=]|\|)/);
console.log(regex);
You can use
(?<=TITLE(?:\|suffix=[^\]|]+)?\|prefix=)[^\]|]+
See the regex demo. Details:
(?<=TITLE(?:\|suffix=[^\]|]+)?\|prefix=) - a location in string immediately preceded with TITLE|prefix| or TITLE|suffix=...|prefix|
[^\]|]+ - one or more chars other than ] and |.
See JavaScript demo:
const texts = ['[TITLE|prefix=a] [STORENAME|prefix=b|suffix=c] [DYNAMIC|limit=10|random=0|reverse=0]', '[TITLE|suffix=s|prefix=a]'];
for (let s of texts) {
console.log(s, '=>', s.match(/(?<=TITLE(?:\|suffix=[^\]|]+)?\|prefix=)[^\]|]+/)[0]);
}
You could also use a capturing group
\[TITLE\|(?:[^|=\]]*=[^|=\]]*\|)*prefix=([^|=\]]*)[^\]]*]
Explanation
\[TITLE\| Match [TITLE|
(?:\w+=\w+\|)* Repeat 0+ occurrences wordchars = wordchars and |
prefix= Match literally
(\w+) Capture group 1, match 1+ word chars
[^\]]* Match any char except ]
] Match the closing ]
Regex demo
const regex = /\[TITLE\|(?:\w+=\w+\|)*prefix=(\w+)[^\]]*\]/g;
const str = `[TITLE|prefix=a] [STORENAME|prefix=b|suffix=c] [DYNAMIC|limit=10|random=0|reverse=0]
[TITLE|suffix=x|prefix=y]`;
let m;
while ((m = regex.exec(str)) !== null) {
console.log(m[1]);
}
Or with a negated character class instead of \w
\[TITLE\|(?:[^|=\]]*=[^|=\]]*\|)*prefix=([^|=\]]*)[^\]]*]
Regex demo

How to slice optional arguments in RegEx?

Actually i have the following RegExp expression:
/^(?:(?:\,([A-Za-z]{5}))?)+$/g
So the accepted input should be something like ,IGORA but even ,IGORA,GIANC,LOLLI is valid and i would be able to slice the string to 3 group in this case, in other the group number should be equals to the user input that pass the RegExp test.
i was trying to do something like this in JavaScript but it return only the last value
var str = ',GIANC,IGORA';
var arr = str.match(/^(?:(?:\,([A-Za-z]{5}))?)+$/).slice(1);
alert(arr);
So the output is 'IGORA' while i would it to be 'GIANC' 'IGORA'
Here is another example
/^([A-Z]{5})(?:(?:\,([A-Za-z]{2}))?)+$/g
test of regexp may have at least 5 chart string but it also can have other 5 chart string separated with a comma so from input
IGORA,CIAOA,POPOP
I would have an array of ["IGORA","CIAOA","POPOP"]
You can capture the words in a capturing surrounded by an optional preceding comma or an optional trailing comma.
You can test the regex here: ,?([A-Za-z]+),?
const pattern = /,?([A-Za-z]+),?/gm;
const str = `,IGORA,GIANC,LOLLI`;
let matches = [];
let match;
// Iterate until no match found
while ((m = pattern.exec(str))) {
// The first captured group is the match
matches.push(m[1]);
}
console.log(matches);
There are other ways to do this, but I found that one of the simple ways is by using the replace method, as it can replace all instances that match that regex.
For example:
var regex = /^(?:(?:\,([A-Za-z]{5}))?)+$/g;
var str = ',GIANC,IGORA';
var arr = [];
str.replace(regex, function(match) {
arr[arr.length] = match;
return match;
});
console.log(arr);
Also, in my code snippet you can see that there is an extra coma in each string, you can solve that by changing line 5 to arr[arr.length] = match.replace(/^,/, '').
Is this what you're looking for?
Explanation:
\b word boundary (starting or ending a word)
\w a word ([A-z])
{5} 5 characters of previous
So it matches all 5-character words but not NANANANA
var str = 'IGORA,CIAOA,POPOP,NANANANA';
var arr = str.match(/\b\w{5}\b/g);
console.log(arr); //['IGORA', 'CIAOA', 'POPOP']
If you only wish to select words separated by commas and nothing else, you can test for them like so:
(?<=,\s*|^) preceded by , with any number of trailing space, OR is the first word in list.
(?=,\s*|$) followed by , and any number of trailing spaces OR is last word in list.
In the following code, POPOP and MOMMA are rejected because they are not separated by a comma, and NANANANA fails because it is not 5 character.
var str = 'IGORA, CIAOA, POPOP MOMMA, NANANANA, MEOWI';
var arr = str.match(/(?<=,\s*|^)\b\w{5}\b(?=,\s*|$)/g);
console.log(arr); //['IGORA', 'CIAOA', 'MEOWI']
If you can't have any trailing spaces after the comma, just leave out the \s* from both (?<=,\s*|^) and (?=,\s*|$).

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