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

/
/
img

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?im)^(.*)@(gmai|ggmail|gmial|gmaol|gmil|iclould|gmeil|iclouds|icoud|hotmial|yahio|gmell|hotmil|gmailz|iclound|gmaio|gmile|gmaul|iclud|gmsil|gamil|ail|gnail|yhoo|gmal|gmaill|yaho|yshoo|gimail|gemail|gmail\.com)\.(com)$`) var str = `a@gmail.com a@gmai.com a@gmial.com a@gmaol.com a@gmil.com a@iclould.com a@gmeil.com a@iclouds.com a@icoud.com a@ggmail.com a@hotmial.com a@yahio.com a@gmell.com a@hotmil.com a@gmailz.com a@iclound.com a@gmaio.com a@gmile.com a@gmaul.com a@iclould.com a@gmaul.com ssssa@iclud.com gmsil.com yahoo.con gamil.com gmail.co ail.com gnail.com gmal.com gail.com yhoo.com hmail.com gmaill.com yaho.com yshoo.com g.mail.com yahoo.co g-mail.com gmail.comm gmail.vom icloud.con hotmail.con gimail.com gmail.cim gemail.com gmail.com.com` 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/