Regular Expressions 101

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Function

  • Match
  • Substitution
  • List
  • Unit Tests (40)

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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

/
/

Unit Tests

given the string 01:00 assert that regex does match
given the string 00:00 AM assert that regex does not match
given the string 02:30 AM assert that regex does match
given the string 01:00 am assert that regex does match
given the string 8:00 pm assert that regex does match
given the string 9.00 AM assert that regex does match
given the string 9.00 assert that regex does match
given the string 8:00PM assert that regex does not match
given the string 8PM assert that regex does not match
given the string 5:59 PM assert that regex does match
given the string 5:59 assert that regex does match
given the string 1: 30 assert that regex does not match
given the string 6:60 PM assert that regex does not match
given the string 6:60 assert that regex does not match
given the string 8:61 PM assert that regex does not match
given the string 8:61 assert that regex does not match
given the string 0:30 PM assert that regex does not match
given the string 13:50 PM assert that regex does not match
given the string 25:00 assert that regex does not match
given the string 12:85 assert that regex does not match
given the string 6:70 PM assert that regex does not match
given the string assert that regex does not match
given the string empty string assert that regex does match
given the string 12:00 PM assert that regex does not match
given the string 1:00 AM assert that regex does not match
given the string 12:00 PM assert that regex does not match
given the string 12:00 PM assert that regex does match
given the string 9:00 AM assert that regex does match
given the string 8:30 PM assert that regex does match
given the string 12:00.00 assert that regex does not match
given the string 12:34:00 assert that regex does not match
given the string 12:123 assert that regex does not match
given the string 123:123 assert that regex does not match
given the string 10:0 assert that regex does not match
given the string 1:0 assert that regex does not match
given the string 123:00 assert that regex does not match
given the string 0:40 assert that regex does match
given the string 1:30 assert that regex does match
given the string 10:00 assert that regex does match
given the string 23:40 assert that regex does match