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)(\.(fit|link)+?)(?:$|\/|\:)`) var str = `ill.com.au@hitme.fit something@hitme.fit something.fit@hitme.fit something.link@hitme.fit 1axcjcbue5xsahq5evlru8vi84l8phe4kd5rmv-user=domain.com.au@5841205t.scamlottery.com 1axcjcbue5xsahq5evlru8vi84l8phe4kd5rmv-user=domain.com.link@5841205t.scamlottery.com no.hit.link@account.fitbit.com no.hit.fit@account.fit.com something@fit.com www.hitme.fitbit/url www.hitme.fitbit:443/url www.hitme.fitbit/url ftp://hitme.good.com/unknown ftp://hitme.fitbit/unknown ftp://hitme.fitbit:23/url.link/ ftps://hitme.good.com/unknown ftps://hitme.fitbit/unknown ftps://hitme.fit:23/url.link/ hitme.fit hitme.fit:443 hitme.fit/link www.hitme.fit www.hitme.fit:443 www.hitme.fit/link https://hitme.fit https://hitme.fit:443 https://hitme.fit/link https://www.hitme.fit https://www.hitme.fit:443 https://www.hitme.fit/link https://hitme.link/transactional/link/6111b67123123fd001d7da8b2/ https://good.link.com/transactional/link.fit/6111b67123123fd001d7da8b2/ https://good.link.com/transactional/fit.link/6111b67123123fd001d7da8b2/ http://www.answers.com/article/1194427/8-habits-of-extraordinarily-likeable-people http://www.apple.com http://www.cnn.com.au/?link.fit/ http://downloads.news.com.au http://ftp.android.co.nz http://global.news.ca http://www.apple.com REV1 (:\/\/)?(\w*\.)*(link)(\/.*)?$ REV2 (\.(fit|link)+?)(?:$|\/|:)` 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/