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)^(?:19|20)\d{2}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12]\d|3[01])T(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:Z|-0[1-9]|-1\d|-2[0-3]|-00:?(?:0[1-9]|[1-5]\d)|\+[01]\d|\+2[0-3])(?:|:?[0-5]\d)$`) var str = `2016-04-14T10:10:11+0000 2016-04-14T10:10:11Z 2016-04-14T10:10:11+0100 2016-04-14T10:10:11+01:00 2016-04-14T10:10:11+01 2016-04-14T10:10:11-0000 2016-04-14T10:10:11-00 2016-00-14T10:10:11+0000 2016-13-14T10:10:11+0000 2016-04-00T10:10:11+0000 2016-04-32T10:10:11+0000 2016-04-01T24:10:11+0000 2016-04-01T00:60:11+0000 2016-04-01T00:00:60+0000 2016-04-01T00:00:00+2400 2016-04-01T00:00:00-2400 ` 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/