Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

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 = "parent\\s*\\{\\s*type\\s*\\{[^\\{\\}]*subtype\\s+TestSubType\\s*\\{[^\\{\\}]*element\\s+TestElement\\s*\\{[^\\{\\}]*attributes\\s*\\{[^\\{\\}]*value\\s+testvalue[^\\{\\}]*\\}[^\\{\\}]*owner\\s+person1"; final String string = "parent {\n" + " type {\n" + " subtype TestSubType {\n" + " element TestElement {\n" + " attributes {\n" + " name testname;\n" + " description testdescription;\n" + " count 1234;\n" + " value testvalue;\n" + " }\n" + " owner person1;\n" + " }\n" + " }\n" + " subtype TestSubType1 {\n" + " element TestElement1 {\n" + " attributes {\n" + " name testname1;\n" + " description testdescription1;\n" + " count 1;\n" + " value 1\n" + " }\n" + " owner person2;\n" + " }\n" + " }\n" + " subtype TestSubType2 {\n" + " element TestElement2 {\n" + " attributes {\n" + " name testname2;\n" + " description testdescription2;\n" + " count 2;\n" + " value 2\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType3 {\n" + " element TestElement3 {\n" + " attributes {\n" + " name testname3;\n" + " description testdescription3;\n" + " count 3;\n" + " value 3\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType3 {\n" + " element TestElement4 {\n" + " attributes {\n" + " name testname4;\n" + " description testdescription4;\n" + " count 4;\n" + " value 4\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType4 {\n" + " element TestElement5 {\n" + " attributes {\n" + " name testname5;\n" + " description testdescription5;\n" + " count 5;\n" + " value 5\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType5 {\n" + " element TestElement6 {\n" + " attributes {\n" + " name testname6;\n" + " description testdescription6;\n" + " count 6;\n" + " value 6\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType6 {\n" + " element TestElement7 {\n" + " attributes {\n" + " name testname7;\n" + " description testdescription7;\n" + " count 7;\n" + " value 7\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType7 {\n" + " element TestElement8 {\n" + " attributes {\n" + " name testname8;\n" + " description testdescription8;\n" + " count 8;\n" + " value 8\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType8 {\n" + " element TestElement9 {\n" + " attributes {\n" + " name testname9;\n" + " description testdescription9;\n" + " count 9;\n" + " value 9\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType9 {\n" + " element TestElement10 {\n" + " attributes {\n" + " name testname10;\n" + " description testdescription10;\n" + " count 10;\n" + " value 10\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " subtype TestSubType10 {\n" + " element TestElement11 {\n" + " attributes {\n" + " name testname11;\n" + " description testdescription11;\n" + " count 11;\n" + " value 11\n" + " }\n" + " owner unknown;\n" + " }\n" + " }\n" + " }\n" + "}\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