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

r"
"
gm

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)\d{3}-\d{4}`) var str = `[Verse 1] Jenny, Jenny, who can I turn to? You give me somethin' I can hold on to I know you think I'm like the others before Who saw your name and number on the wall [Chorus 1] Jenny, I got your number I need to make you mine Jenny, don't change your number [Post-Chorus] 867-5309 867-5309 867-5309 867-5309 [Verse 2] Jenny, Jenny, you're the girl for me Oh, you don't know me, but you make me so happy I tried to call you before, but I lost my nerve I tried my imagination, but I was disturbed [Chorus 1] Jenny, I got your number I need to make you mine Jenny, don't change your number [Post-Chorus] 867-5309 867-5309 867-5309 867-5309 [Bridge] I got it, (I got it), I got it I got your number on the wall I got it, (I got it), I got it For a good time, for a good time call [Chorus 2] Jenny, don't change your number I need to make you mine Jenny, I call your number [Post-Chorus] 867-5309 867-5309 867-5309 867-5309 [Breakdown] Jenny, Jenny, who can I turn to? 867-5309 For the price of a dime I can always turn to you 867-5309 [Outro] 867-5309 867-5309 867-5309 867-5309 5309 867-5309 (5309) 867-5309 (5309) 867-5309` 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/