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

r"
"
g

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(\\w+)(?:(?:@)|(?:\\s+[Aa][Tt]\\s+))(.+)(?:(?:\\.edu)|(?:\\s+[dD][oO][Tt]\\s+edu))"; final String string = "ashishg e ashishg@stanford.edu\n" + "ashishg e rozm@stanford.edu\n" + "ashishg p 650-723-1614\n" + "ashishg p 650-723-4173\n" + "ashishg p 650-814-1478\n" + "balaji e balaji@stanford.edu\n" + "bgirod p 650-723-4539\n" + "bgirod p 650-724-3648\n" + "bgirod p 650-724-6354\n" + "cheriton e cheriton@cs.stanford.edu\n" + "cheriton e uma@cs.stanford.edu\n" + "cheriton p 650-723-1131\n" + "cheriton p 650-725-3726\n" + "dabo e dabo@cs.stanford.edu\n" + "dabo p 650-725-3897\n" + "dabo p 650-725-4671\n" + "dlwh e dlwh@stanford.edu\n" + "engler e engler@lcs.mit.edu\n" + "engler e engler@stanford.edu\n" + "eroberts e eroberts@cs.stanford.edu\n" + "eroberts p 650-723-3642\n" + "eroberts p 650-723-6092\n" + "fedkiw e fedkiw@cs.stanford.edu\n" + "hager e hager@cs.jhu.edu\n" + "hager p 410-516-5521\n" + "hager p 410-516-5553\n" + "hager p 410-516-8000\n" + "hanrahan e hanrahan@cs.stanford.edu\n" + "hanrahan p 650-723-0033\n" + "hanrahan p 650-723-8530\n" + "horowitz p 650-725-3707\n" + "horowitz p 650-725-6949\n" + "jks e jks@robotics.stanford.edu\n" + "jurafsky e jurafsky@stanford.edu\n" + "jurafsky p 650-723-5666\n" + "kosecka e kosecka@cs.gmu.edu\n" + "kosecka p 703-993-1710\n" + "kosecka p 703-993-1876\n" + "kunle e darlene@csl.stanford.edu\n" + "kunle e kunle@ogun.stanford.edu\n" + "kunle p 650-723-1430\n" + "kunle p 650-725-3713\n" + "kunle p 650-725-6949\n" + "lam e lam@cs.stanford.edu\n" + "lam p 650-725-3714\n" + "lam p 650-725-6949\n" + "latombe e asandra@cs.stanford.edu\n" + "latombe e latombe@cs.stanford.edu\n" + "latombe e liliana@cs.stanford.edu\n" + "latombe p 650-721-6625\n" + "latombe p 650-723-0350\n" + "latombe p 650-723-4137\n" + "latombe p 650-725-1449\n" + "levoy e ada@graphics.stanford.edu\n" + "levoy e melissa@graphics.stanford.edu\n" + "levoy p 650-723-0033\n" + "levoy p 650-724-6865\n" + "levoy p 650-725-3724\n" + "levoy p 650-725-4089\n" + "manning e dbarros@cs.stanford.edu\n" + "manning e manning@cs.stanford.edu\n" + "manning p 650-723-7683\n" + "manning p 650-725-1449\n" + "manning p 650-725-3358\n" + "nass e nass@stanford.edu\n" + "nass p 650-723-5499\n" + "nass p 650-725-2472\n" + "nick e nick.parlante@cs.stanford.edu\n" + "nick p 650-725-4727\n" + "ok p 650-723-9753\n" + "ok p 650-725-1449\n" + "ouster e teresa.lynn@stanford.edu\n" + "ouster e ouster@cs.stanford.edu\n" + "pal e pal@cs.stanford.edu\n" + "pal p 650-725-9046\n" + "psyoung e patrick.young@stanford.edu\n" + "rajeev p 650-723-4377\n" + "rajeev p 650-723-6045\n" + "rajeev p 650-725-4671\n" + "rinard e rinard@lcs.mit.edu\n" + "rinard p 617-253-1221\n" + "rinard p 617-258-6922\n" + "serafim e serafim@cs.stanford.edu\n" + "serafim p 650-723-3334\n" + "serafim p 650-725-1449\n" + "shoham e shoham@stanford.edu\n" + "shoham p 650-723-3432\n" + "shoham p 650-725-1449\n" + "subh e subh@stanford.edu\n" + "subh e uma@cs.stanford.edu\n" + "subh p 650-724-1915\n" + "subh p 650-725-3726\n" + "subh p 650-725-6949\n" + "thm e pkrokel@stanford.edu\n" + "thm p 650-725-3383\n" + "thm p 650-725-3636\n" + "thm p 650-725-3938\n" + "tim p 650-724-9147\n" + "tim p 650-725-2340\n" + "tim p 650-725-4671\n" + "ullman e support@gradiance.com\n" + "ullman e ullman@cs.stanford.edu\n" + "ullman p 650-494-8016\n" + "ullman p 650-725-2588\n" + "ullman p 650-725-4802\n" + "vladlen e vladlen@stanford.edu\n" + "widom e siroker@cs.stanford.edu\n" + "widom e widom@cs.stanford.edu\n" + "widom p 650-723-0872\n" + "widom p 650-723-7690\n" + "widom p 650-725-2588\n" + "zelenski e zelenski@cs.stanford.edu\n" + "zelenski p 650-723-6092\n" + "zelenski p 650-725-8596\n" + "zm e manna@cs.stanford.edu\n" + "zm p 650-723-4364\n" + "zm p 650-725-4671\n" + "650-725-4671\n" + "650-725-4671\n" + "6103564533\n" + "(610)3564533\n" + "(610) 356-4533 \n" + "610.405.0420\n" + "6104050420\n" + "16104050420\n" + "610.405-0420\n" + "610.405-0420\n\n\n\n\n"; final Pattern pattern = Pattern.compile(regex); 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