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

/
/
gm

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)<a class="list-group-item list-group-item-action " href="https:\/\/moodle-hs-ulm\.de\/course\/view\.php\?id=([0-9]*)"(?:.*\s){7}<span class="media-body ">([^<]*)<\/span>`) var str = `<nav class="list-group"> <a class="list-group-item list-group-item-action active" href="https://moodle-hs-ulm.de/" data-key="home" data-isexpandable="0" data-indent="0" data-showdivider="0" data-type="1" data-nodetype="1" data-collapse="0" data-forceopen="1" data-isactive="1" data-hidden="0" data-preceedwithhr="0"> <div class="m-l-0"> <div class="media"> <span class="media-left"> <i class="icon fa fa-home fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body font-weight-bold">Startseite</span> </div> </div> </a> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/my/" data-key="home" data-isexpandable="0" data-indent="0" data-showdivider="0" data-type="70" data-nodetype="0" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="home"> <div class="m-l-0"> <div class="media"> <span class="media-left"> <i class="icon fa fa-tachometer fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">Dashboard</span> </div> </div> </a> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/calendar/view.php?view=month" data-key="calendar" data-isexpandable="0" data-indent="0" data-showdivider="0" data-type="60" data-nodetype="0" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="1"> <div class="m-l-0"> <div class="media"> <span class="media-left"> <i class="icon fa fa-calendar fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">Kalender</span> </div> </div> </a> <div class="list-group-item" data-key="mycourses" data-isexpandable="1" data-indent="0" data-showdivider="0" data-type="0" data-nodetype="1" data-collapse="0" data-forceopen="1" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="home"> <div class="m-l-0"> <div class="media"> <span class="media-left"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body">Meine Kurse</span> </div> </div> </div> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/course/view.php?id=88" data-key="88" data-isexpandable="0" data-indent="1" data-showdivider="0" data-type="20" data-nodetype="1" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="mycourses"> <div class="m-l-1"> <div class="media"> <span class="media-left"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">Algorithmen und Datenstrukturen INF3 (WS18/19)</span> </div> </div> </a> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/course/view.php?id=397" data-key="397" data-isexpandable="0" data-indent="1" data-showdivider="0" data-type="20" data-nodetype="1" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="mycourses"> <div class="m-l-1"> <div class="media"> <span class="media-left"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">Analysis 2 für Informatiker</span> </div> </div> </a> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/course/view.php?id=646" data-key="646" data-isexpandable="0" data-indent="1" data-showdivider="0" data-type="20" data-nodetype="1" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="mycourses"> <div class="m-l-1"> <div class="media"> <span class="media-left"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">Daba</span> </div> </div> </a> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/course/view.php?id=67" data-key="67" data-isexpandable="0" data-indent="1" data-showdivider="0" data-type="20" data-nodetype="1" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="mycourses"> <div class="m-l-1"> <div class="media"> <span class="media-left"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">Einführung in MATLAB</span> </div> </div> </a> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/course/view.php?id=551" data-key="551" data-isexpandable="0" data-indent="1" data-showdivider="0" data-type="20" data-nodetype="1" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="mycourses"> <div class="m-l-1"> <div class="media"> <span class="media-left"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">i²</span> </div> </div> </a> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/course/view.php?id=277" data-key="277" data-isexpandable="0" data-indent="1" data-showdivider="0" data-type="20" data-nodetype="1" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="mycourses"> <div class="m-l-1"> <div class="media"> <span class="media-left"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">Mobile App Dev</span> </div> </div> </a> <a class="list-group-item list-group-item-action " href="https://moodle-hs-ulm.de/course/view.php?id=631" data-key="631" data-isexpandable="0" data-indent="1" data-showdivider="0" data-type="20" data-nodetype="1" data-collapse="0" data-forceopen="0" data-isactive="0" data-hidden="0" data-preceedwithhr="0" data-parent-key="mycourses"> <div class="m-l-1"> <div class="media"> <span class="media-left"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" aria-label=""></i> </span> <span class="media-body ">Programmieren III / INF3A</span> </div> </div> </a> </nav>` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", 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 Golang, please visit: https://golang.org/pkg/regexp/