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

/
/
g

Test String

Code Generator

Language

Generated Code

re = /[^\w](?<!->)(trans|trans_choice|Lang::get|Lang::choice|Lang::trans|Lang::transChoice|@lang|@choice|__)\s*\(\s*((?<![\\])['"])((?:.(?!(?<![\\])\2))*.?)\2\s*[,\)]/ str = 'Should match variations on method: trans(\'a.b\'); trans_choice(\'a.b\') Lang::get(\'a.b\'); Lang::choice(\'a.b\', 1); Lang::trans(\'a.b\'); Lang::transChoice(\'a.b\', 2); @lang(\'language.line\') @choice(\'language.line\', 1); __(\'a.b\') Should match variations of contained string trans(\'key\'); // No group, so JSON style __(\'Json string\') trans(\'a.b\'); trans(\'a.b.c\'); trans(\'a_b.c-d\'); trans(\'a.b!\'); trans(\'a.translate me!\'); trans(\'a.über~\'); trans("app.i\'m"); // contained quote of different type trans(\'app."ok"\'); trans(\'with contained " quotes\'); trans(\'with an escaped \\\' quote\') trans(\'with a double \\\\\') Should match additional variables and whitespace trans(\'a.b\', [1,2]); trans ( \' with whitespace \' , $var) Typical use cases (trans ( \'lang.line\')); <span>@lang(\'lang.line\')</span> Should not match: trans($var); // No quotes trans(); // Nothing anytrans(\'group.key\'); // not the method we need 1trans(\'lang.file\'); // not the method _trans(\'lang.file\'); // not the method ->trans(\'lang.line\'); trans(\\\'why do we have an escaped quote here?\\\') trans(\'with a triple \\\\\\\') <-- fail! trans(\'lang.line\' . $middle); // concatenated vars trans(\'lang.line\' . $middle . \'.ending\'); // concatenated vars ___(\'hello\') // not the method we need ' # 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