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

/
/
ig

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 = "\\b(?:(?:ht|f)tp(?:s?)\\:\\/\\/|~\\/|\\/)?(?:\\w+:\\w+@)?((?:(?:[-\\w\\d\\{1-3\\}]+\\.)+(?:com|org|net|gov|mil|biz|info|mobi|name|aero|jobs|edu|co\\.uk|ac\\.uk|it|fr|tv|museum|asia|local|travel|[a-z]{2}))|((\\b25[0-5]\\b|\\b[2][0-4][0-9]\\b|\\b[0-1]?[0-9]?[0-9]\\b)(\\.(\\b25[0-5]\\b|\\b[2][0-4][0-9]\\b|\\b[0-1]?[0-9]?[0-9]\\b)){3}))(?::[\\d]{1,5})?(?:(?:(?:\\/(?:[-\\w~!$+|.,=]|%[a-f\\d]{2})+)+|\\/)+|\\?|#)?(?:(?:\\?(?:[-\\w~!$+|.,*:]|%[a-f\\d{2}])+=?(?:[-\\w~!$+|.,*:=]|%[a-f\\d]{2})*)(?:&(?:[-\\w~!$+|.,*:]|%[a-f\\d{2}])+=?(?:[-\\w~!$+|.,*:=]|%[a-f\\d]{2})*)*)*(?:#(?:[-\\w~!$ |\\/.,*:;=]|%[a-f\\d]{2})*)?\\b"; final String string = "# valid\n" + "http://www.google.com\n" + "ftp://example.com\n" + "google.com\n" + "a.google.com\n" + "a.google.com/b/~user\n" + "http://www.google.com/~user\n" + "www.google.com/sdfa/asdf?f93+3234\n" + "accounts.google.com\n" + "valid.domain.com/foasdf/~23423lj\n" + "accounts.google.com/login?res=sdfs sdf\n" + "accounts.google.com\n" + "you.name\n" + "you.name/~joe\n" + "google.com/+joe\n" + "https://joe:test@test.com\n\n" + "# partial \n" + "http://joe@test.com\n\n\n" + "# invalid\n" + "not: \n" + "ftp://example\n" + "something.asfdasjdlf;\n" + "abc.def@#$90fai\n" + "something.like.this\n" + "abc.def\n\n\n"; final Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE); 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