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

/
/
is

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 = "(?:cmdlet|get-alias)|(?:help.+?(?:cmdlet|get-alias))"; final String string = "PS M:\\> get-help\n" + "TOPIC\n" + " Get-Help\n\n" + "SHORT DESCRIPTION\n" + " Displays help about Windows PowerShell cmdlets and concepts.\n\n" + "LONG DESCRIPTION\n\n" + "SYNTAX\n" + " get-help {<CmdletName> | <TopicName>}\n" + " help {<CmdletName> | <TopicName>}\n" + " <CmdletName> -?\n\n" + " \"Get-help\" and \"-?\" display help on one page.\n" + " \"Help\" displays help on multiple pages.\n\n" + " Examples:\n" + " get-help get-process : Displays help about the Get-Process cmdlet.\n" + " get-help about_signing : Displays help about signing scripts.\n" + " help where-object : Displays help about the Where-Object cmdlet.\n" + " help about_foreach : Displays help about foreach loops in PowerShell.\n" + " set-service -? : Displays help about the Set-Service cmdlet.\n\n" + " You can use wildcard characters in the help commands (not with -?).\n" + " If multiple help topics match, PowerShell displays a list of matching\n" + " topics. If only one help topic matches, PowerShell displays the topic.\n\n" + " Examples:\n" + " get-help * : Displays all help topics.\n" + " get-help get-* : Displays topics that begin with get-.\n" + " help *object* : Displays topics with \"object\" in the name.\n" + " get-help about* : Displays all conceptual topics.\n\n\n" + " For information about wildcards, type:\n" + " get-help about_wildcard\n\n\n" + "REMARKS\n" + " To learn about Windows PowerShell, read the following help topics:\n" + " get-command : Gets information about cmdlets from the cmdlet code.\n" + " get-member : Gets the properties and methods of an object.\n" + " where-object : Filters object properties.\n" + " about_object : Explains the use of objects in Windows PowerShell.\n" + " about_remote : Tells how to run commands on remote computers.\n\n" + " Conceptual help files are named \"about_<topic>\", such as:\n" + " about_regular_expression.\n\n" + " The names of conceptual help files must be entered in English\n" + " even on non-English versions of Windows PowerShell.\n\n" + " The help commands also display the aliases of the cmdlets. These\n" + " are alternate names or nicknames that are often easier to type.\n" + " For example, the alias for the Invoke-Command cmdlet is \"remote\".\n\n" + " To get the aliases, type:\n\n" + " get-alias\n" + "PS M:\\>"; final Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE | Pattern.DOTALL); final Matcher matcher = pattern.matcher(string); if (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