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

/
/
gim

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

re = /("(post\s*(office)?)?\s*box\s*[#-]?\s*(\d+)?"|"[\w\s]*?p(ost)?\s*[.-]?\s*o?\s*\.?\s*b?(ox)?\.?\s*(\d+)?"|"\s*number\s*\d+")/im str = ' "Box 123", "Box-122", "Box122", "HC73 P.O. Box 217", "P O Box125", "P. O. Box", "P.O 123", "P.O. Box 123", "P.O. Box", "P.O.B 123", "P.O.B. 123", "P.O.B.", "POB 123", "POB", "POBOX123", "Po Box", "Post 123", "Post Box 123", "Post Office Box 123", "Post Office Box", "box #123", "box 122", "box 123", "number 123", "p box", "p-o box", "post office box" "The Postal Road", "Box Hill", "123 Some Street", "Controller\'s Office", "pollo St.", "123 box canyon rd", "777 Post Oak Blvd", "PSC 477 Box 396", "RR 1 Box 1020"' subst = '' 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