Regular Expressions 101

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Function

  • Match
  • Substitution
  • List
  • Unit Tests (17)

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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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

/
/
gm

Unit Tests

given the string M1 1AA assert that regex does match
given the string M11AA assert that regex does match
given the string M60 1NW assert that regex does match
given the string M601NW assert that regex does match
given the string CR2 6XH assert that regex does match
given the string CR26XH assert that regex does match
given the string DN55 1PT assert that regex does match
given the string DN551PT assert that regex does match
given the string W1P 1HQ assert that regex does match
given the string W1P1HQ assert that regex does match
given the string EC1A 1BB assert that regex does match
given the string EC1A1BB assert that regex does match
given the string TEST assert that regex does not match
given the string _ assert that regex does not match
given the string M1_1AA assert that regex does not match
given the string 33014 assert that regex does not match
given the string POST COD assert that regex does not match