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

/
/
gx

Test String

Code Generator

Generated Code

const regex = /(?mi) ^ (?! \h* (?: [A-Z] \h* \. | ANSWER \h* : ) ) \h* (?<question> \S .*? ) # (1) \?? \h* \s* ^ \h* A \h* \. \h* (?<A> .*? ) # (2) \h* \s* (?: ^ \h* B \h* \. \h* (?<B> .*? ) # (3) \h* (?: \s* ^ \h* C \h* \. \h* (?<C> .*? ) # (4) \h* (?: \s* ^ \h* D \h* \. \h* (?<D> .*? ) # (5) \h* (?: \s* ^ \h* E \h* \. \h* (?<E> .*? ) # (6) \h* )? )? )? )? \s* ^ \h* ANSWER \h* : \h* (?<answer1> [A-F] ) # (7) (?: \h* , \h* (?<answer2> [A-F] ) # (8) )? /g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?mi) ^ (?! \\h* (?: [A-Z] \\h* \\. | ANSWER \\h* : ) ) \\h* (?<question> \\S .*? ) # (1) \\?? \\h* \\s* ^ \\h* A \\h* \\. \\h* (?<A> .*? ) # (2) \\h* \\s* (?: ^ \\h* B \\h* \\. \\h* (?<B> .*? ) # (3) \\h* (?: \\s* ^ \\h* C \\h* \\. \\h* (?<C> .*? ) # (4) \\h* (?: \\s* ^ \\h* D \\h* \\. \\h* (?<D> .*? ) # (5) \\h* (?: \\s* ^ \\h* E \\h* \\. \\h* (?<E> .*? ) # (6) \\h* )? )? )? )? \\s* ^ \\h* ANSWER \\h* : \\h* (?<answer1> [A-F] ) # (7) (?: \\h* , \\h* (?<answer2> [A-F] ) # (8) )? ', 'g') const str = `Linux is A. A Graphic Software B. A Driver C. A Line Controller Software D. An Operating System ANSWER: D Which feature helps in compress and contain the collection of files in to one A. Zip B. Shortcut C. Icon D. Extract ANSWER: A What is php? A. Php is a language. B. Php creates HTML. C. Php is fun. D. none of these. ANSWER: D Which is YII-2? A. Framework. B. Tool. C. None of these ANSWER: A,B`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions