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

/
/
i

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?i)(?=_{20,}|From:|On\s\w{3},\s\w{3}\s\d{1,2},\s\d{4}\sat\s\d{1,2}:\d{2})`) var str = `Great thank you ________________________________ From: Blake <blake@foursocial.uk> Sent: Saturday, August 31, 2024 9:46:12 AM To: blake hoang <bjh2004@hotmail.co.uk> Subject: Re: Ignition. Campaign Thanks , yes we can do it --- Blake Junior Managing Director | Foursocial. blake@foursocial.uk<mailto:blake@foursocial.uk> Submission Links<https://linktr.ee/foursocial1> [https://ci3.googleusercontent.com/mail-sig/AIorK4yeSFbHM5imdVzOjDTr7LwNvS9gqpyQ83uajylr7mDBuRn5ymG1jlev6Zz8vvgQMzDLAYjFLcR7LVLu] On Sat, Aug 31, 2024 at 9:45 AM blake hoang <bjh2004@hotmail.co.uk<mailto:bjh2004@hotmail.co.uk>> wrote: Hey there let me know the fee` if len(re.FindStringIndex(str)) > 0 { fmt.Println(re.FindString(str),"found at index",re.FindStringIndex(str)[0]) } }

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/