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

/
/

Test String

Substitution

Processing...

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 = "\\h*<xen:if is=\"\\{\\$debugMode\\}\">\n" + "\\h*<xen:if hascontent=\"true\">\n" + "\\h*<dl class=\"pairsInline debugInfo\".*?>\n" + "(\\h*)<xen:contentcheck>"; final String string = "<xen:edithint template=\"footer.css\" />\n\n" + "<xen:hook name=\"footer\">\n" + "<div class=\"footer\">\n" + " <div class=\"pageWidth\">\n" + " <div class=\"pageContent\">\n" + " <xen:if is=\"{$canChangeStyle} OR {$canChangeLanguage}\">\n" + " <dl class=\"choosers\">\n" + " <xen:if is=\"{$canChangeStyle}\">\n" + " <dt>{xen:phrase style}</dt>\n" + " <dd><a href=\"{xen:link 'misc/style', '', 'redirect={$requestPaths.requestUri}'}\" class=\"OverlayTrigger Tooltip\" title=\"{xen:phrase style_chooser}\" rel=\"nofollow\">{$visitorStyle.title}</a></dd>\n" + " </xen:if>\n" + " <xen:if is=\"{$canChangeLanguage}\">\n" + " <dt>{xen:phrase language}</dt>\n" + " <dd><a href=\"{xen:link 'misc/language', '', 'redirect={$requestPaths.requestUri}'}\" class=\"OverlayTrigger Tooltip\" title=\"{xen:phrase language_chooser}\" rel=\"nofollow\">{$visitorLanguage.title}</a></dd>\n" + " </xen:if>\n" + " </dl>\n" + " </xen:if>\n" + " \n" + " <ul class=\"footerLinks\">\n" + " <xen:hook name=\"footer_links\">\n" + " <xen:if is=\"{$xenOptions.contactUrl.type} === 'default'\">\n" + " <li><a href=\"{xen:link 'misc/contact'}\" class=\"OverlayTrigger\" data-overlayOptions=\"{&quot;fixed&quot;:false}\">{xen:phrase contact_us}</a></li>\n" + " <xen:elseif is=\"{$xenOptions.contactUrl.type} === 'custom'\" />\n" + " <li><a href=\"{$xenOptions.contactUrl.custom}\" {xen:if {$xenOptions.contactUrl.overlay}, 'class=\"OverlayTrigger\" data-overlayOptions=\"{&quot;fixed&quot;:false}\"'}>{xen:phrase contact_us}</a></li>\n" + " </xen:if>\n" + " <li><a href=\"{xen:link help}\">{xen:phrase help}</a></li>\n" + " <xen:if is=\"{$homeLink}\"><li><a href=\"{$homeLink}\" class=\"homeLink\">{xen:phrase home}</a></li></xen:if>\n" + " <li><a href=\"{$requestPaths.requestUri}#navigation\" class=\"topLink\">{xen:phrase go_to_top}</a></li>\n" + " <li><a href=\"{xen:link forums/-/index.rss}\" rel=\"alternate\" class=\"globalFeed\" target=\"_blank\"\n" + " title=\"{xen:phrase rss_feed_for_x, 'title={$xenOptions.boardTitle}'}\">{xen:phrase rss}</a></li>\n" + " </xen:hook>\n" + " </ul>\n" + " \n" + " <span class=\"helper\"></span>\n" + " </div>\n" + " </div>\n" + "</div>\n\n" + "<div class=\"footerLegal\">\n" + " <div class=\"pageWidth\">\n" + " <div class=\"pageContent\">\n" + " <ul id=\"legal\">\n" + " <xen:hook name=\"footer_links_legal\">\n" + " <xen:if is=\"{$tosUrl}\"><li><a href=\"{$tosUrl}\">{xen:phrase terms_and_rules}</a></li></xen:if>\n" + " <xen:if is=\"{$xenOptions.privacyPolicyUrl}\"><li><a href=\"{$xenOptions.privacyPolicyUrl}\">{xen:phrase privacy_policy}</a></li></xen:if>\n" + " </xen:hook>\n" + " </ul>\n" + " \n" + " <div id=\"copyright\">{xen:helper copyright} {xen:phrase extra_copyright}</div>\n" + " <xen:hook name=\"footer_after_copyright\" />\n" + " \n" + " <xen:if is=\"{$debugMode}\">\n" + " <xen:if hascontent=\"true\">\n" + " <dl class=\"pairsInline debugInfo\" title=\"{$controllerName}-&gt;{$controllerAction}{xen:if $viewName, ' ({$viewName})'}\">\n" + " <xen:contentcheck>\n" + " <xen:if is=\"{$page_time}\"><dt>{xen:phrase timing}:</dt> <dd><a href=\"{$debug_url}\" rel=\"nofollow\">{xen:phrase x_seconds, 'time={xen:number $page_time, 4}'}</a></dd></xen:if>\n" + " <xen:if is=\"{$memory_usage}\"><dt>{xen:phrase memory}:</dt> <dd>{xen:phrase x_mb, 'size={xen:number {xen:calc \"{$memory_usage} / 1024 / 1024\"}, 3}'}</dd></xen:if>\n" + " <xen:if is=\"{$db_queries}\"><dt>{xen:phrase db_queries}:</dt> <dd>{xen:number {$db_queries}}</dd></xen:if>\n" + " </xen:contentcheck>\n" + " </dl>\n" + " </xen:if>\n" + " </xen:if>\n" + " \n" + " <span class=\"helper\"></span>\n" + " </div>\n" + " </div> \n" + "</div>\n" + "</xen:hook>"; final String subst = "$0\\n$1 <!-- Adding XenForo version strings -->\\n$1 <dt>XenForo Version:<dt> <dd>{$xenOptions.currentVersion} ({$xenOptions.currentVersionId})</dd>\\n\\n"; final Pattern pattern = Pattern.compile(regex); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceFirst(subst); System.out.println("Substitution result: " + result); } }

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