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

/
/
igu

Test String

Code Generator

Language

Generated Code

re = /\B(([\/]{0,}#(?:(?![×Þß÷þø]))([-'_0-9a-zÀ-ÿ]){1,})+)/i str = '#hashtag a #hashtag a #hashtag world cool.#hashtag ##hashtag, but only until the comma and starting at second hash #hashtag1#hashtag2 two separate matches https://stackoverflow.com/questions/ask#notHashTag Word#notHashTag #ab is not too short to be a hashtag I #love #chocolate Hi #future-me. How are you? Hi #fíre gone #allée #allèàoùî Hi there #a#b #hello Hi\\nthere how#are you #doing now? #dog Hi there #tag. # Hi\\nHow are you? https://notium.org/some-url#something https://notium.org/some-url/#something #some_word .#toto # Markdown Example Markdown allows you to easily include formatted text, images, and even formatted Dart code in your app. ## Titles Setext-style This is an H1 ============= This is an H2 ------------- Atx-style # This is an H1 ## This is an H2 ###### This is an H6 Select the valid headers: - [x] # hello - [ ] #hello ## Links [Google\'s Homepage][Google] [inline-style](https://www.google.com) [reference-style][Google] ## Images ## Tables |Syntax |Result | |---------------------------------------|-------------------------------------| |*italic 1* |italic 1 | |_italic 2_ | italic 2 | |**bold 1** |bold 1 | |__bold 2__ |bold 2 | |This is a ~~strikethrough~~ |This is a strikethrough | |***italic bold 1*** |italic bold 1 | |___italic bold 2___ |italic bold 2 | |***~~italic bold strikethrough 1~~***|***italic bold strikethrough 1***| |~~***italic bold strikethrough 2***~~|italic bold strikethrough 2| ## Styling Style text as italic, bold, strikethrough, or inline code. - Use bulleted lists - To better clarify - Your points ## Code blocks Formatted Dart code looks really pretty too: void main() { runApp(MaterialApp( home: Scaffold( body: Markdown(data: markdownData), ), )); } ## Markdown widget This is an example of how to create your own Markdown widget: Markdown(data: \'Hello world!\'); Enjoy! [Google]: https://www.google.com/ # DateTimeOffset #csharp Provides a combined #structure\\tof `DateTime` with an `Offset` property defining a deviation from UTC. It doesn\'t associate a time zone with the offset.' # 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