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JRebel
jrebel.com › blog › java-regular-expressions-cheat-sheet
Java Regular Expressions (Regex) Cheat Sheet | JRebel
July 30, 2025 - In our Regular Expressions cheat sheet, we include essential Java classes and methods, Regex syntax, character classes, boundary matchers, logical operations, quantifiers, groups, backreferences, and pattern flags.
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Rexegg
rexegg.com › regex-quickstart.php
Regex Cheat Sheet
Regular Expressions Syntax Reference. Includes tables showing syntax, examples and matches.
Discussions
I finally sat down and learned RegEx lookarounds. Here's a cheat sheet I made.
Oh man... someone hated regex so hard he made this website : https://ihateregex.io/ It is quite famous tho.. More on reddit.com
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Regex Cheat Sheet📝
Just use: https://regex101.com/ More on reddit.com
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February 21, 2019
Understanding the Java regex pattern example - Stack Overflow
I have gone through the Java doc for regular expressions and based on the document I can see that the pattern here is using "Capturing Groups" But I am not able to understand how the pattern in my example works, what is its meaning and how it is able to extract data from input string. Can someone please help me in understanding this code. ... Do you have an understanding of what regex ... More on stackoverflow.com
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Cheatsheets for Regex
regex101 is quite useful too More on reddit.com
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QuickRef.ME
quickref.me › home › regex cheat sheet & quick reference
RegEX Cheat Sheet & Quick Reference
A quick reference for regular expressions (regex), including symbols, ranges, grouping, assertions and some sample patterns to get you started. This is a quick cheat sheet to getting started with regular expressions.
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W3Schools
w3schools.com › java › java_regex.asp
Java Regular Expressions
import java.util.regex.Matcher; import java.util.regex.Pattern; public class Main { public static void main(String[] args) { Pattern pattern = Pattern.compile("w3schools", Pattern.CASE_INSENSITIVE); Matcher matcher = pattern.matcher("Visit W3Schools!"); boolean matchFound = matcher.find(); if(matchFound) { System.out.println("Match found"); } else { System.out.println("Match not found"); } } } // Outputs Match found
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GeeksforGeeks
geeksforgeeks.org › java › regular-expressions-in-java
Regular Expressions in Java - GeeksforGeeks
May 22, 2026 - In Java, regular expressions are supported through the java.util.regex package, which mainly consists of the following classes:
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Code4libtoronto
code4libtoronto.github.io › 2018-10-12-access › GoogleRefineCheatSheets.pdf pdf
Cheat Sheet: Regular Expressions
Cheat Sheet: Regular Expressions · Adapted from http://www.javacodegeeks.com/2012/11/java-regular-expression-tutorial-with-examples.html. Matching symbols · Regex · Matches · . any one character · ^abc · “abc” at the beginning of a line · abc$ “abc” at the end of a line ·
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Oracle
docs.oracle.com › javase › 8 › docs › api › java › util › regex › Pattern.html
Pattern (Java Platform SE 8 )
July 21, 2026 - A regular expression, specified as a string, must first be compiled into an instance of this class. The resulting pattern can then be used to create a Matcher object that can match arbitrary character sequences against the regular expression. All of the state involved in performing a match ...
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Medium
medium.com › nerd-for-tech › regular-expressions-cheat-sheet-ab86a1207735
Regular Expressions cheat sheet. A Regular Expression (or Regex) is a… | by Rohan Aggarwal | Nerd For Tech | Medium
May 28, 2021 - Regular Expressions cheat sheet A Regular Expression (or Regex) is a pattern (or filter) that describes a set of strings that matches the pattern. Regular expressions are used to search strings for a …
Find elsewhere
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Medium
medium.com › @kaustubh.saha › regular-expressions-in-java-b806152aaa93
Regular Expressions in Java. A regular expression is essentially a… | by Kaustubh Saha | Medium
November 29, 2025 - Regular Expressions in Java A regular expression is essentially a search pattern defined by a sequence of characters. While String methods like contains(), startsWith(), or indexOf() are great for …
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Pinterest
pinterest.com › pin › java-8-lambdas-java-collections-zeroturnaroundcom--658721882972855637
Java Regular Expressions (Regex) Cheat Sheet | JRebel
Java Regular Expressions Cheat Sheet | Java regex reference guide, Java syntax cheat sheet, Javascript regular expression cheat sheet · Skip to content · When autocomplete results are available use up and down arrows to review and enter to select. Touch device users, explore by touch or with ...
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Reddit
reddit.com › r/learnprogramming › i finally sat down and learned regex lookarounds. here's a cheat sheet i made.
r/learnprogramming on Reddit: I finally sat down and learned RegEx lookarounds. Here's a cheat sheet I made.
July 24, 2020 -

Overall, quite a pain in the butt! I haven't found a website that teaches these well yet. I ended up doing exercises from multiple different websites. I'm finally getting a handle on them.

Anyway, here's a cheat sheet I made to help me remember lookarounds (and some other RegEx stuff I haven't memorized yet). Enjoy.

https://ibb.co/4gZb2gP

edit: I ended up posting this on my blog

Top answer
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Oh man... someone hated regex so hard he made this website : https://ihateregex.io/ It is quite famous tho..
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Great job! They are SO powerful and no one likes them. That is why learning REGEX is a valuable asset to have. You can make a career out of doing/learning things no one else wants to.
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testRigor
testrigor.com › home › blog › your regex cheat sheet
Your RegEx Cheat Sheet - testRigor AI-Based Automated Testing Tool
April 14, 2025 - How does regex work? How to write RegEx expressions? This comprehensive cheat sheet will help you!
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CoderPad
coderpad.io › regular-expression-cheat-sheet
Regular Expression Cheat Sheet - CoderPad
April 14, 2022 - DownloadRead the Full Regex Guide
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MIT
web.mit.edu › hackl › www › lab › turkshop › slides › regex-cheatsheet.pdf pdf
Regular Expressions cheat sheet
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Reddit
reddit.com › r/programming › regex cheat sheet📝
r/programming on Reddit: Regex Cheat Sheet📝
February 21, 2019 - I finally sat down and learned RegEx lookarounds. Here's a cheat sheet I made.
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RStudio
rstudio.github.io › cheatsheets › regex.pdf pdf
Basic Regular Expressionsin R Cheat Sheet Updated: 07/19Qua *
Cheat Sheet · Updated: 07/19 · Quantifiers · * Matches at least 0 times · + Matches at least 1 time · ? Matches at most 1 time; optional string · {n} Matches exactly n times · {n,} Matches at least n times · {n,m} Matches between n and m times · Functions · f ·
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Mozilla
developer.mozilla.org › en-US › docs › Web › JavaScript › Guide › Regular_expressions › Cheatsheet
Regular expression syntax cheat sheet - JavaScript | MDN
2 weeks ago - This page provides an overall cheat sheet of all the capabilities of RegExp syntax by aggregating the content of the articles in the RegExp guide. If you need more information on a specific topic, please follow the link on the corresponding heading to access the full article or head to the guide.
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Stack Overflow
stackoverflow.com › questions › 22986634 › understanding-the-java-regex-pattern-example
Understanding the Java regex pattern example - Stack Overflow
Top answer
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Hope this helps:

Pattern 1: ^(/?test/[^/]+)/([^/]+)(/?.*)$

group 1: (/?test/[^/]+) = "/test/hello"
group 2: ([^/]+) = "world"
group 3: (/?.*) = "/checking/"

Pattern 2: ^(/?test)/([^/]+)(/?.*)$

group 1: (/?test) = "/test"
group 2: ([^/]+) = "hello"
group 3: (/?.*) = "world/checking/"

Hints:

/?test - the slash is optional = "test", "/test"
[^/] - anything else than a slash = "hello", "world", "$#* abc",...
[^/]+ - the plus stands for 1 or more times = "a", "aa",...
/?.* - optional slash and any character 0 or more times = "","/","a","/a",...

^,$,?,.,*,[] - regex operators, you can google their meaning.

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GitHub
gist.github.com › vitorbritto › 9ff58ef998100b8f19a0
Regex Cheat Sheet · GitHub
Regex Cheat Sheet · Raw · regex.md · /.../: Start and end regex delimiters · |: Alternation · (): Grouping · ^: Start of string or start of line in multi-line mode · \A: Start of string · $: End of string or end of line in multi-line mode · \Z: End of string ·