Category: Javascript regex square brackets

Javascript regex square brackets

20.10.2020 By Mektilar

By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. It was also literally interpreting the 1 which wasn't matching.

Your above code isn't working, because it's trying to match "[]" sequentially without anything allowed between. We can get around this by non-greedy group-matching. Also if the sequential brackets have separators spaces etc it won't match. It's pretty useful :. Two backslashes produces a single backslash, so you're searching for "a backslash, followed by a character class consisting of a 1 or a right bracketand then you're missing an closing bracket.

I stumbled on this question while dealing with square bracket escaping within a character class that was designed for use with password validation requiring the presence of special characters.

As rudu mentions, this expression is within a string so it must be double escaped.

javascript regex square brackets

Here is an example of using square brackets in a character class that tests for all the special characters found on my keyboard:. How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. How can I put [] square brackets in RegExp javascript? Ask Question. Asked 8 years, 8 months ago. Active 1 year, 2 months ago. Viewed 49k times. Active Oldest Votes.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. If you want something that only captures the group from MDN :. I'm not sure if you can get this directly into an array. But the following code should work to find all occurences and then process them:.

Otherwise in my test the expression would match the hole string because ] is also matches by. Learn more. Regex to grab strings between square brackets Ask Question.

Subscribe to RSS

Asked 8 years, 7 months ago. Active 2 years, 4 months ago. Viewed 19k times. RobG k 23 23 gold badges silver badges bronze badges. Active Oldest Votes. Kobi Kobi k 36 36 gold badges silver badges bronze badges.

Get a text inside square brackets with regex ( regular expressions )

I am struggling to parse the array content in multiline. Here is the example. James Kyburz James Kyburz Chris Chris 6, 8 8 gold badges 42 42 silver badges 89 89 bronze badges. Matches str1 ; you can use foreach for matched strings. Suriya Suriya 8 8 silver badges 13 13 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name.

Email Required, but never shown. The Overflow Blog. The Overflow How many jobs can be done at home? Featured on Meta. Community and Moderator guidelines for escalating issues via new response….By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information.

To be strictly equivalent, you would code? The reason these regexes are similar is that a character class is a shorthand for an "or" but only for single characters. In an alternation, you can also do something like abc def which does not translate to a character class.

Your team's advice is almost right, except for the mistake that was made. Once you find out why, you will never forget it. Take a look at this mistake. The use of php which runs on PCRE for preg matching will optimize away the lack of backtracking, however we're not in PHP either, so using classes [] instead of alternations gives performance bonus as the match does not backtrack, and therefore both matches and fails faster than using your previous regular expression. If you match on this:.

Learn more. What is the difference between square brackets and parentheses in a regex? Ask Question. Asked 8 years ago. Active 5 months ago. Viewed k times. The first number is supposed to be any of 7, 8 or 9. Tim Pietzcker k 53 53 gold badges silver badges bronze badges. Jayapal Chandran Jayapal Chandran 7, 12 12 gold badges 61 61 silver badges 84 84 bronze badges. Active Oldest Votes. B--rian 2, 4 4 gold badges 21 21 silver badges 42 42 bronze badges. If you use between []do the brackets behave differently?

DanielKaplan don't use within a character class [ Also duplicating chars in a character class has no effect - a character class is a list of characters and will match exactly one of them.

The string will only match if the subpattern matches the entirety of it, not just a section. It does this with alternationswhich is what the pipe operator does — alternating between alternations. This backtracks between alternations: If the first alternation is not matched, the engine has to return before the pointer location moved during the match of the alternation, to continue matching the next alternation; Whereas the character class can advance sequentially.

Any characters from the list 7, 8, or 9 can be matched, thus the was added in incorrectly. This matches without backtracking. The combination of the use of a character class and a single metacharacter is a bad idea, by the way, since the layer of abstraction can slow down the match, but this is only an implementation detail and only applies to a few of regex implementations. JavaScript is not one, but it does make the subpattern slightly longer.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Here is refrence from where i got this. This fiddle uses RegExp. How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. RegEx to get text from inside the square brackets [duplicate] Ask Question.

Asked 7 years, 10 months ago. Active 7 years, 9 months ago. Viewed 21k times. Here is refrence from where i got this here is what i have done so far demo please help.

Active Oldest Votes. Could the look ahead regex not be simplified? Jules: good suggestion, thanks. Sir can you please explain me what is happening in for loop and can we use underscore.

The Overflow Blog. Podcast Cryptocurrency-Based Life Forms. Q2 Community Roadmap. Featured on Meta. Community and Moderator guidelines for escalating issues via new response…. Feedback on Q2 Community Roadmap.

javascript regex square brackets

Triage needs to be fixed urgently, and users need to be notified upon…. Dark Mode Beta - help us root out low-contrast and un-converted bits. Technical site integration observational experiment live on Stack Overflow. Linked Related Hot Network Questions. Stack Overflow works best with JavaScript enabled.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. To be strictly equivalent, you would code?

javascript regex square brackets

The reason these regexes are similar is that a character class is a shorthand for an "or" but only for single characters. In an alternation, you can also do something like abc def which does not translate to a character class. Your team's advice is almost right, except for the mistake that was made. Once you find out why, you will never forget it. Take a look at this mistake. The use of php which runs on PCRE for preg matching will optimize away the lack of backtracking, however we're not in PHP either, so using classes [] instead of alternations gives performance bonus as the match does not backtrack, and therefore both matches and fails faster than using your previous regular expression.

If you match on this:. How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. What is the difference between square brackets and parentheses in a regex? Ask Question. Asked 8 years ago. Active 5 months ago. Viewed k times. The first number is supposed to be any of 7, 8 or 9. Tim Pietzcker k 53 53 gold badges silver badges bronze badges. Jayapal Chandran Jayapal Chandran 7, 12 12 gold badges 61 61 silver badges 84 84 bronze badges.

Active Oldest Votes. B--rian 2, 4 4 gold badges 21 21 silver badges 42 42 bronze badges. If you use between []do the brackets behave differently?

DanielKaplan don't use within a character class [ Also duplicating chars in a character class has no effect - a character class is a list of characters and will match exactly one of them.

The string will only match if the subpattern matches the entirety of it, not just a section. It does this with alternationswhich is what the pipe operator does — alternating between alternations. This backtracks between alternations: If the first alternation is not matched, the engine has to return before the pointer location moved during the match of the alternation, to continue matching the next alternation; Whereas the character class can advance sequentially.

Any characters from the list 7, 8, or 9 can be matched, thus the was added in incorrectly. This matches without backtracking. The combination of the use of a character class and a single metacharacter is a bad idea, by the way, since the layer of abstraction can slow down the match, but this is only an implementation detail and only applies to a few of regex implementations. JavaScript is not one, but it does make the subpattern slightly longer. Unihedron Unihedron 9, 10 10 gold badges 49 49 silver badges 63 63 bronze badges.

I just found this out the hard way. Alan Moore By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Here is refrence from where i got this. This fiddle uses RegExp. Learn more. RegEx to get text from inside the square brackets [duplicate] Ask Question.

Asked 7 years, 10 months ago. Active 7 years, 9 months ago. Viewed 21k times. Here is refrence from where i got this here is what i have done so far demo please help. Active Oldest Votes.

Could the look ahead regex not be simplified? Jules: good suggestion, thanks. Sir can you please explain me what is happening in for loop and can we use underscore. The Overflow Blog. The Overflow How many jobs can be done at home? Featured on Meta. Community and Moderator guidelines for escalating issues via new response….

Feedback on Q2 Community Roadmap. Technical site integration observational experiment live on Stack Overflow. Triage needs to be fixed urgently, and users need to be notified upon…. Dark Mode Beta - help us root out low-contrast and un-converted bits. Linked Related Hot Network Questions.

Stack Overflow works best with JavaScript enabled.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information.

Learn more. How to remove square brackets in string using regex? Ask Question. Asked 9 years, 6 months ago. Active 4 years, 6 months ago. Viewed 86k times. Gumbo k 95 95 gold badges silver badges bronze badges.

Mugdha Mugdha 2 2 gold badges 5 5 silver badges 12 12 bronze badges. Where does this string come from? Is this JSON or something similar? Could the square brackets be nested? Is this a JavaScript literal? Active Oldest Votes.

Regex Tester

Mark Byers Mark Byers k gold badges silver badges bronze badges. Zypps [ Consequently, if you want to match [ and ] characters, you need to escape them so that they're interpreted as simple characters. The first bracket within the character class doesn't have to be escaped. Fourier Fourier 1 1 silver badge 6 6 bronze badges.