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 single character of: a, b, c or d
    [[ab][cd]]
  • 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]
  • Character class intersection
    [\w&&[^\d]]
  • 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 = /^(?<year>\d{4})[-\/](?<month>0[1-9]|1[0-2])[-\/](?<day>0[1-9]|[1-2][0-9]|3[0-1])(?:[T\s](?:(?<hour>0[0-9]|1[0-9]|2[0-4]):(?<minute>\d{2}):(?<second>\d{2})(?:\.(?<nano>\d+))?))?(?:(?<offset>[Zz]|(?:[+-])(?:[01]\d|2[0-3])(?::?[0-5]\d)?)?)$/m str = '2020-12-01T12:13:51.123+02:00 2020-12-01T12:13:51.123+0200 2020-12-01T12:13:51.123Z 2020-12-01T12:13:51.123 2020-12-01T12:13:51.123341512+02:00 2020-12-01T12:13:51.123341512+0200 2020-12-01T12:13:51.123341512Z 2020-12-01T12:13:51.123341512 2020-12-01T12:13:51+02:00 2020-12-01T12:13:51+0200 2020-12-01T12:13:51Z 2020-12-01T12:13:51 2020-12-01 12:13:51.123 +02:00 2020-12-01 12:13:51.123 +0200 2020-12-01 12:13:51.123Z 2020-12-01 12:13:51.123 2020-12-01 12:13:51.123341512 +02:00 2020-12-01 12:13:51.123341512 +0200 2020-12-01 12:13:51.123341512Z 2020-12-01 12:13:51.123341512 2020-12-01 12:13:51+02:00 2020-12-01 12:13:51+0200 2020-12-01 12:13:51Z 2020-12-01 12:13:51 2020-12-01+02:00 2020-12-01+0200 2020-12-01Z 2020-12-01 2020/12/01T12:13:51.123+02:00 2020/12/01T12:13:51.123+0200 2020/12/01T12:13:51.123Z 2020/12/01T12:13:51.123 2020/12/01T12:13:51.123341512+02:00 2020/12/01T12:13:51.123341512+0200 2020/12/01T12:13:51.123341512Z 2020/12/01T12:13:51.123341512 2020/12/01T12:13:51+02:00 2020/12/01T12:13:51+0200 2020/12/01T12:13:51Z 2020/12/01T12:13:51 2020/12/01+02:00 2020/12/01+0200 2020/12/01Z 2020/12/01 2039/15/23 2923/09/12 2023/23/51 2020-12-01T00:13:51 2020-12-01T01:13:51 2020-12-01T10:13:51 2020-12-01T19:13:51 2020-12-01T20:13:51 2020-12-01T24:13:51' subst = '$1-$2-$3' 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