Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^\\s*at\\s((?!webpack:).)*:\\d+:\\d+[\\s\\)]*\\n"; final String string = "\n" + "/src/components/compare/couples/index.jsx\n\n" + "/Users/james/Work/nib/GithubEnterprise/frontend/react-static-example/src/components/compare/couples/index.jsx\n" + " 23:5 error Parsing error: Unexpected token {\n\n" + "✖ 1 problem (1 error, 0 warnings)\n\n" + "BabelLoaderError: SyntaxError: Unexpected token (23:4)\n\n" + " 21 | const Couples = ({products}) => (\n" + " 22 | <div>%%><\n" + "> 23 | {Foobar}\n" + " | ^\n" + " 24 | <Heading size=\"1\">Couples</Heading>\n" + " 25 | <img className=\"banner\" src={img}/>\n" + " 26 | <ul>\n\n" + " at transpile (/Users/james/Work/nib/GithubEnterprise/frontend/react-static-example/node_modules/babel-loader/index.js:52:13)\n" + " at /Users/james/Work/nib/GithubEnterprise/frontend/react-static-example/node_modules/babel-loader/lib/fs-cache.js:151:18\n" + " at ReadFileContext.callback (/Users/james/Work/nib/GithubEnterprise/frontend/react-static-example/node_modules/babel-loader/lib/fs-cache.js:29:23)\n" + " at FSReqWrap.readFileAfterOpen [as oncomplete] (fs.js:303:13)\n\n" + "static-react-render-webpack-plugin: Error rendering page \"scripts/components/compare/couples.js\": ReferenceError: Foobar is not defined\n" + " at Couples (webpack:///./components/compare/couples/index.jsx?:37:5)\n" + " at eval (webpack:///../~/react/lib/ReactCompositeComponent.js?:305:16)\n" + " at measureLifeCyclePerf (webpack:///../~/react/lib/ReactCompositeComponent.js?:74:12)\n" + " at ReactCompositeComponentMixin._constructComponentWithoutOwner (webpack:///../~/react/lib/ReactCompositeComponent.js?:304:14)\n" + " at ReactCompositeComponentMixin._constructComponent (webpack:///../~/react/lib/ReactCompositeComponent.js?:279:21)\n" + " at ReactCompositeComponentMixin.mountComponent (webpack:///../~/react/lib/ReactCompositeComponent.js?:187:21)\n" + " at Object.ReactReconciler.mountComponent (webpack:///../~/react/lib/ReactReconciler.js?:47:35)\n" + " at ReactDOMComponent.ReactMultiChild.Mixin.mountChildren (webpack:///../~/react/lib/ReactMultiChild.js?:240:44)\n" + " at ReactDOMComponent.Mixin._createContentMarkup (webpack:///../~/react/lib/ReactDOMComponent.js?:661:32)\n" + " at ReactDOMComponent.Mixin.mountComponent (webpack:///../~/react/lib/ReactDOMComponent.js?:528:29)\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html