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

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 = "^([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x22([^\\x0d\\x22\\x5c\\x80-\\xff]|\\x5c[\\x00-\\x7f])*\\x22)(\\x2e([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x22([^\\x0d\\x22\\x5c\\x80-\\xff]|\\x5c[\\x00-\\x7f])*\\x22))*\\x40([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x5b([^\\x0d\\x5b-\\x5d\\x80-\\xff]|\\x5c[\\x00-\\x7f])*\\x5d)(\\x2e([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x5b([^\\x0d\\x5b-\\x5d\\x80-\\xff]|\\x5c[\\x00-\\x7f])*\\x5d))*$"; final String string = "criscrisaaaa@gmail.com.es\n" + "mminighin@alpenite.com\n" + "!mminighin@alpenite.com\n" + "#mminighin@alpenite.com\n" + "$mminighin@alpenite.com\n" + "%mminighin@alpenite.com\n" + "&mminighin@alpenite.com\n" + "'mminighin@alpenite.com\n" + "*mminighin@alpenite.com\n" + "+mminighin@alpenite.com\n" + "-mminighin@alpenite.com\n" + "/mminighin@alpenite.com\n" + "=mminighin@alpenite.com\n" + "?mminighin@alpenite.com\n" + "^mminighin@alpenite.com\n" + "_mminighin@alpenite.com\n" + "`mminighin@alpenite.com\n" + "{mminighin@alpenite.com\n" + "|mminighin@alpenite.com\n" + "}mminighin@alpenite.com\n" + "~mminighin@alpenite.com\n" + "0mminighin@alpenite.com\n" + "1mminighin@alpenite.com\n" + "2mminighin@alpenite.com\n" + "3mminighin@alpenite.com\n" + "4mminighin@alpenite.com\n" + "5mminighin@alpenite.com\n" + "6mminighin@alpenite.com\n" + "7mminighin@alpenite.com\n" + "8mminighin@alpenite.com\n" + "9mminighin@alpenite.com\n" + "10mminighin@alpenite.com\n" + "prettyandsimple@example.com\n" + "very.common@example.com\n" + "disposable.style.email.with+symbol@example.com\n" + "other.email-with-dash@example.com\n" + "fully-qualified-domain@example.com\n" + "user.name+tag+sorting@example.com\n" + "x@example.com\n" + "\"very.(),:;<>[]\\\".VERY.\\\"very@\\\\ \\\"very\\\".unusual\"@strange.example.com\n" + "example-indeed@strange-example.com\n" + "admin@mailserver1\n" + "#!$%&'*+-/=?^_`{}|~@example.org\n" + "\"()<>[]:,;@\\\\\\\"!#$%&'-/=?^_`{}| ~.a\"@example.org\n" + "example@s.solutions\n" + "user@localserver\n" + "user@[2001:DB8::1]\n" + ".user@[2001:DB8::1]"; final String subst = ""; 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