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

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 = "<a href=\\\"([^\\\"]+)\\\"[^/]*>([^<]*)<"; final String string = "<p><a href=\"http://www.quackit.com/html/tutorial/html_links.cfm\">Example Link</a></p>\n" + "<div class=\"more-info\"><a href=\"http://www.quackit.com/html/examples/html_links_examples.cfm\">More Link Examples...</a></div>\n\n" + "<li id=\"n-mainpage-description\"><a href=\"/wiki/Main_Page\" title=\"Visit the main page [z]\" accesskey=\"z\"><b>Main page</b></a></li>\n\n" + "<center>\n" + "<div class=\"noresize\" style=\"height: 242px; width: 600px; \"><map name=\"ImageMap_1_971996215\" id=\"ImageMap_1_971996215\">\n" + "<area href=\"/wiki/File:Pardalotus_punctatus_female_with_nesting_material_-_Risdon_Brook.jpg\" shape=\"rect\" coords=\"3,3,297,238\" alt=\"Female\" title=\"Female\" />\n" + "<area href=\"/wiki/File:Pardalotus_punctatus_male_with_nesting_material_-_Risdon_Brook.jpg\" shape=\"rect\" coords=\"302,2,597,238\" alt=\"Male\" title=\"Male\" /></map><img alt=\"Pair of Spotted Pardalotes\" src=\"//upload.wikimedia.org/wikipedia/commons/thumb/5/5b/Female_and_male_Pardalotus_punctatus.jpg/600px-Female_and_male_Pardalotus_punctatus.jpg\" width=\"600\" height=\"242\" srcset=\"//upload.wikimedia.org/wikipedia/commons/thumb/5/5b/Female_and_male_Pardalotus_punctatus.jpg/900px-Female_and_male_Pardalotus_punctatus.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5b/Female_and_male_Pardalotus_punctatus.jpg/1200px-Female_and_male_Pardalotus_punctatus.jpg 2x\" usemap=\"#ImageMap_1_971996215\" />\n" + "<div style=\"margin-left: 0px; margin-top: -20px; text-align: left;\"><a href=\"/wiki/File:Female_and_male_Pardalotus_punctatus.jpg\" title=\"About this image\"><img alt=\"About this image\" src=\"//bits.wikimedia.org/static-1.22wmf7/extensions/ImageMap/desc-20.png\" style=\"border: none;\" /></a></div>\n" + "</div>\n" + "</center>"; 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