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

/
/
gmi

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?mi)<\w+.*?\K[\w-]+=["']*\s*(?:\w+\s*)*[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,}\s*(?:['"]?(?:\w+\s*)*['"]?)?["']*(?=.*?>)`) var str = `<br data-a1="nope" attr=" jepp@get.me " data-a2="nope"> <br data-a1="nope" attr=' jepp@get.me ' data-a2="nope"> <br data-a1="nope" attr=jepp@get.me data-a2="nope"> <br data-a1="nope" attr=" jepp@get.me " data-a2="nope"/> <br data-a1="nope" attr=" jepp@get.me " data-a2="nope" /> <tag data-a1="nope" attr=" jepp@get.me " data-a2="nope">text</tag> <tag data-a1="nope" attr=' jepp@get.me ' data-a2="nope">text</tag> <tag data-a1="nope" attr=jepp@get.me data-a2="nope">text</tag> <tag data-a1="nope" attr=" additional text jepp@get.me 'additional text'" data-a2="nope">text</tag> <tag data-a1="nope" attr=" additional text jepp@get.me additional text" data-a2="nope">text</tag> <tag data-a1="nope" attr=' additional text jepp@get.me "additional text"' data-a2="nope">text</tag> <tag data-a1="nope" attr=" jepp@get.me jeppagain@get.me " data-a2="nope">text</tag> abc dont@get.me 123 <input value="please@get.me">xyz abc dont@get.me 123 <tag1 att1="val1" email1="please@get.me">xyz abc dont@get.me 123 <tag2 att1="val1" email2="please@get.me" att1="val1">xyz <tag2 att1="val1" email3='please@get.me' att1="val1">xyz <tag2 att1="val1" email4=please@get.me att1="val1">xyz <tag2 att1="val1" email5=" please@get.me " att1="val1">xyz <tag2 att1="val1" email6=' please@get.me ' att1="val1">xyz <tag data-yeah-also-valid-attr-name="please@get.me">xyz <tag data-yeah-attr="please@get.me"> <tag data-yeah-attr='please@get.me'> <tag data-yeah-attr=please@get.me> <tag data-yeah-attr="'please@get.me'"> <tag data-yeah-attr='"please@get.me"'>` 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/