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

/
/
gmx

Test String

Code Generator

Language

Generated Code

re = /^" # opening quote (?:\\ # accept a literal backslash if it (?: # if it's followed by ["\\\/bfnrt] # one of the magic characters | # or u[\da-fA-F]{8} # a unicode character ) | # or, if it's not # a backslash-escaped character [^"\\] # we accept anything that isn't # a doublequote, backslash, # or possibly \r or \n )* # zero or more of these # acceptable-content items "$ # the requisite closing quote/mx str = '\\uff009ea1 \\t \\\\ \\b \\uff009ea1\\t\\\\\\b \\uff009ea1\\\\\\b "Hello there, 123 !@&^#%! what???\'\'" "Hello there 123 what" "Hello there, 123 !@&\\t\\\\\\b^#%! what???\'\'" "Hello there \\uff009ea1\\t\\\\\\b 123 what"' # Print the match result str.scan(re) do |match| puts match.to_s end

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