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

Substitution

Processing...

Code Generator

Language

Generated Code

re = /(.*)(-)(.*)(-)(.*)/m str = '10-10-2017 10-10-2017 10-10-2017 10-1-2018 10-1-2018 10-1-2018 10-1-2018 10-1-2018 10-1-2018 10-2-2018 10-2-2018 10-2-2018 10-3-2018 10-3-2018 10-7-2017 10-7-2017 10-7-2017 10-7-2017 10-7-2017 10-7-2017 10-7-2017 10-8-2017 10-8-2017 10-8-2017 10-8-2017 10-9-2017 10-9-2017 1-10-2017 1-10-2017 1-10-2017 1-10-2017 11-10-2017 11-10-2017 11-11-2017 11-11-2017 11-11-2017 11-11-2017 1-112017 1-11-2017 1-11-2017 1-11-2017 1-11-2017 1-11-2017 11-1-2018 11-1-2018 11-1-2018 11-1-2018 1-1-2017 1-1-2018 1-1-2018 1-1-2018 11-2-2018 11-2-2018 11-2-2018 11-7-2017 12-11-2017 1-2-2018 1-2-2018 1-2-2018 1-2-2018 12-2-2018 12-2-2018 12-2-2018 12-2-2018 12-2-2018 12-2-2018 12-3-2018 12-3-2018 12-3-2018 12-3-2018 12-3-2018 12-3-2018 12-3-2018 12-7-2017 12-7-2017 12-7-2017 12-7-2017 12-7-2017 12-7-2017 12-7-2017 12-9-2017 13-11-2017 13-11-2017 13-11-2017 13-1-2018 13-1-2018 13-1-2018 1-3-2018 1-3-2018 13-6-2017 13-7-2017 13-7-2017 13-7-2017 13-7-2017 13-7-2017 13-7-2017 13-7-2017 13-8-2017 13-8-2017 13-8-2017 13-8-2017 13-8-2017 13-9-2017 13-9-2017 13-9-2017 14-10-2017 14-10-2017 14-10-2017 14-11-2017 14-11-2017 14-11-2017 14-1-2018 14-1-2018 1-4-2018 1-4-2018 1-4-2018 14-2-2018 14-3-2018 14-3-2018 14-3-2018 14-3-2018 14-3-2018 14-3-2018 14-7-2017 14-8-2017 14-8-2017 14-8-2017 15-10-2017 15-10-2017 15-11-2017 15-11-2017 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-2-2018 15-2-2018 15-2-2018 15-2-2018 15-3-2018 15-3-2018 15-7-2017 15-7-2017 15-7-2017 15-7-2017 15-7-2017 16-10-2017 16-10-2017 16-10-2017 16-10-2017 16-11-2017 16-11-2017 16-11-2017 16-11-2017 16-1-2018 16-7-2017 16-7-2017 16-7-2017 16-8-2017 16-8-2017 16-9-2017 16-9-2017 16-9-2017 16-9-2017 16-9-2017 17-10-2017 17-10-2017 17-10-2017 17-11-2017 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-2-2018 17-2-2018 17-2-2018 17-3-2018 17-3-2018 17-3-2018 17-7-2017 17-7-2017 17-7-2017 17-7-2017 17-7-2017 17-7-2017 17-9-2017 17-9-2017 17-9-2017 18-10-2017 18-10-2017 18-10-2017 18-10-2017 18-10-2017 18-11-2017 18-11-2017 18-1-2018 18-1-2018 18-1-2018 18-1-2018 18-1-2018 1-8-2017 1-8-2017 1-8-2017 1-8-2017 18-2-2018 18-3-2018 18-3-2018 18-3-2018 18-7-2017 18-7-2017 18-7-2017 18-7-2017 18-7-2017 18-7-2017 18-9-2017 19-10-2017 19-10-2017 19-10-2017 19-10-2017 19-10-2017 19-11-2017 19-11-2017 19-2-2018 19-2-2018 19-2-2018 19-3-2018 19-3-2018 19-3-2018 19-3-2018 19-3-2018 19-3-2018 19-8-2017 19-8-2017 19-8-2017 19-8-2017 20-1-2018 20-1-2018 20-1-2018 20-1-2018 20-1-2018 20-1-2018 20-1-2018 ' subst = '\\5\\4\\3\\2\\1' result = str.gsub(re, subst) # Print the result of the substitution puts result

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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html