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]
  • Character class intersection
    [\w&&[^\d]]
  • 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

Substitution
Processing...

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 = "interface (\\w+)(\\s+)\\{([?\\w\\s\\d:;()\\[\\]=>\\.]*)\\};"; final String string = "/**\n" + " * Analytic instance returned from initialization\n" + " * @property identify - Identify a user\n" + " * @property track - Track an analytics event\n" + " * @property page - Trigger page view\n" + " * @property user - Get user data\n" + " * @property reset - Clear information about user & reset analytics\n" + " * @property ready - Fire callback on analytics ready event\n" + " * @property on - Fire callback on analytics lifecycle events.\n" + " * @property once - Fire callback on analytics lifecycle events once.\n" + " * @property getState - Get data about user, activity, or context.\n" + " * @property storage - storage methods\n" + " * @property plugins - plugin methods\n" + " */ \n" + "export interface AnalyticsInstance {\n" + " identify: Identify;\n" + " track: Track;\n" + " page: Page;\n" + " user: User;\n" + " reset: Reset;\n" + " ready: Ready;\n" + " on: On;\n" + " once: Once;\n" + " getState: GetState;\n" + " storage: Storage;\n" + " plugins: Plugins;\n" + " };\n\n" + "interface AnalyticsPluginBase {\n" + " name: string;\n" + " EVENTS?: any;\n" + " config?: any;\n" + " initialize?: (...params: any[]) => any;\n" + " page?: (...params: any[]) => any;\n" + " track?: (...params: any[]) => any;\n" + " identify?: (...params: any[]) => any;\n" + " loaded?: (...params: any[]) => any;\n" + " ready?: (...params: any[]) => any;\n" + "};"; final String subst = "interface $1$2{$3}"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceAll(subst); System.out.println("Substitution result: " + result); } }

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