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
Processing...

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 = "^\n" + "#whitespace\n" + "([ ]*)\n" + "(?:\n" + " # Error position - line location \n" + " (-{6,})([\\^])\n" + " |\n" + " # Line number\n" + " ([\\d]+)\n" + " # Line number delim\n" + " ([\\|])\n" + " # Code indent\n" + " ([ \\t]*)\n" + " (?:\n" + " # Comment ?\n" + " ([\\/]{2}.+)?\n" + " |\n" + " # Else code block line\n" + " (.*)\n" + " )\n" + " $\n" + ")\n" + "|\n" + "# Function delim token\n" + "(at +)\n" + "# Function\n" + "(.+?)\n" + "# (, Path base\n" + "([\\(].+?)\n" + "# File\n" + "([^\\/]+?)\n" + "# Line:char\n" + "(?:(:)(\\d+))?\n" + "(?:(:)(\\d+))?\n" + "# Function path\n" + "([\\)])"; final String string = " watching /Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/functions/index.styl\n" + "ParseError: inject/code-custom.styl:125:44\n" + " 121| else\n" + " 122| // Add room for window controls\n" + " 123| body.mac \n" + " 124| // Only target first tab bar\n" + " 125| [data-keybinding-context=\"1\"] .tabs-and-actions-container\n" + "---------------------------------------------------^\n" + " 126| & .tabs-and-actions-container\n" + " 127| padding-left: 9em\n" + " 128| & .dragging-area-left-padding\n\n" + "expected \":\", got \")\"\n\n" + " at Parser.error (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:259:11)\n" + " at Parser.expect (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:287:12)\n" + " at Parser.ternary (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1964:12)\n" + " at Parser.negation (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1953:17)\n" + " at Parser.expression (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1932:24)\n" + " at Parser.ternary (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1963:27)\n" + " at Parser.negation (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1953:17)\n" + " at Parser.expression (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:1932:24)\n" + " at Parser.primary (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:2250:23)\n" + " at Parser.member (/Users/disk0/.nvm/versions/node/v13.2.0/lib/node_modules/stylus/lib/parser.js:2174:21)\n" + " compiled inject/FontLoad.css\n" + " watching inject/FontLoad.styl\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.COMMENTS); 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