Regular Expressions 101

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Function

  • Match
  • Substitution
  • List
  • Unit Tests (13)

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An explanation of your regex will be automatically generated as you type.
  • 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

/
/

Unit Tests

given the string ABC.N assert that regex does not match
given the string RJN.P assert that regex does not match
given the string RJN.OQ assert that regex does match
given the string LALT.N assert that regex does match
given the string R.N assert that regex does match
given the string L.N assert that regex does match
given the string RACE.N assert that regex does match
given the string LAZ.N assert that regex does match
given the string RRD.OQ assert that regex does match
given the string RAX.OQ assert that regex does match
given the string LB.OQ assert that regex does match
given the string LLL.OQ assert that regex does match
given the string LALT.OQ assert that regex does not match