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

/
/
gm

Test String

Code Generator

Language

Generated Code

re = /<(?!\/*strong\W|\/*h1\W|\/*input\W|\/*b\W).*?>/m str = '<form action="#" method="post"> <div> <label for="name">Text Input:</label> <input type="text" name="name" id="name" value="" tabindex="1" /> </div> <div> <h4>Radio Button Choice</h4> <label for="radio-choice-1">Choice 1</label> <input type="radio" name="radio-choice-1" id="radio-choice-1" tabindex="2" value="choice-1" /> <label for="radio-choice-2">Choice 2</label> <input type="radio" name="radio-choice-2" id="radio-choice-2" tabindex="3" value="choice-2" /> </div> <div> <label for="select-choice">Select Dropdown Choice:</label> <select name="select-choice" id="select-choice"> <option value="Choice 1">Choice 1</option> <option value="Choice 2">Choice 2</option> <option value="Choice 3">Choice 3</option> </select> </div> <div> <label for="textarea">Textarea:</label> <textarea cols="40" rows="8" name="textarea" id="textarea"></textarea> </div> <div> <label for="checkbox">Checkbox:</label> <input type="checkbox" name="checkbox" id="checkbox" /> </div> <div> <input type="submit" value="Submit" /> </div> </form>' # 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