Regular Expressions 101

Save & Manage Regex

  • Current Version: 3
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
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
Processing...

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 = "(?P<issuetime>\\d+/\\w+Z)(?:\\s+(?P<layer>\\w+/\\w+|NOT\\s+AVBL)(?:\\s+(?P<coordinates>(?:\\w\\d{4}\\s\\w\\d{5}\\s-\\s)+\\w\\d{4}\\s\\w\\d{5}\\s))*)?"; final String string = "FCST VA CLD +6 HR: 16/1200Z SFC/FL200 N4517 W04623 - N6356 W01924 -\n" + "N7750 E07729 - N3856 E06031 - N4517 W04623 FL200/350 N4839 W04904 -\n" + "N7025 E01017 - N7505 E07954 - N6139 E06549 - N4839 W04904\n" + "FCST VA CLD +12 HR: 16/1800Z SFC/FL200 N4010 E03817 - N4900 W04529 -\n" + "N7112 W00641 - N7617 E09941 - N4010 E03817 FL200/350 N4919 W05700 -\n" + "N7300 E03329 - N7732 E09626 - N5936 E09143 - N4919 W05700\n" + "FCST VA CLD +18 HR: 17/0000Z SFC/FL200 N4901 W05420 - N7235 E00056 -\n" + "N7558 E09708 - N3934 E05131 - N4901 W05420 FL200/350 N4933 W03842 -\n" + "N5436 W04127 - N7433 E03732 - N7935 E11430 - N6503 E10238 - N4933\n" + "W03842\n" + "FCST VA CLD +6 HR: 16/1200Z SFC/FL200 N4517 W04623 - N6356 W01924\n" + "FCST VA CLD +12 HR: 16/1800Z NOT AVBL\n" + "FCST VA CLD +18 HR: 17/0000Z NOT AVBL RET\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); 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