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

const regex = /(?:(?:Jr|Master|Mr|Ms|Mrs|Dr|Capt|Col|Sgt|Sr|Prof|Rep|Mt|Mount|St|Etc|Eg)\.\s+|["'“(\[]?)(?:\b(?:(?!(?:\S{1,})[.?!]+["']?\s+["']?[A-Z]).)*)(?:(?:(?:Jr|Master|Mr|Ms|Mrs|Dr|Capt|Col|Sgt|Sr|Prof|Rep|Mt|Mount|St|Etc|Eg)\.\s+(?:(?!\w{2,}[.?!]['"]?\s+["']?[A-Z]).)*)?)*(?:(?![.?!]["']?\s+["']?\w).)*(?:[.?!)\]]+["'”]?|[^\r\n]+$)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?:(?:Jr|Master|Mr|Ms|Mrs|Dr|Capt|Col|Sgt|Sr|Prof|Rep|Mt|Mount|St|Etc|Eg)\\.\\s+|["\'“(\\[]?)(?:\\b(?:(?!(?:\\S{1,})[.?!]+["\']?\\s+["\']?[A-Z]).)*)(?:(?:(?:Jr|Master|Mr|Ms|Mrs|Dr|Capt|Col|Sgt|Sr|Prof|Rep|Mt|Mount|St|Etc|Eg)\\.\\s+(?:(?!\\w{2,}[.?!][\'"]?\\s+["\']?[A-Z]).)*)?)*(?:(?![.?!]["\']?\\s+["\']?\\w).)*(?:[.?!)\\]]+["\'”]?|[^\\r\\n]+$)', 'gm') const str = `PROBLEM: "This is a problem. You hear me?" Possible problem/exception sentence (Does not properly split due to "Mr."): On Feb. 20 Mr. X said "Beyond the fourth wall, there shall be 'light'"?!... Or something. Second sentence. Third. Possible problem/exception ("Really?" should not split before Capital names?: "Really?" Mr. baker asked, as he proceeded to ponder. This is a new line without ending punctuation Ending punctuation problem solved, almost Yep it solved 'Dr. T.G. Walker alarmed the whole 20.50 train when Mr. T.G. Walker got up shouting at 10 o'clock.' "The exchange rate was at 500.72." After the crowd dissipated the police also went home. 'Mr. Sherlock Holmes and Dr. John Watson and Mrs. Williams together with T.G. Hooker and Capt. Marshall, of course, were better than the F.B.I. at crime fighting. Feb. 20 Mr. Barack Obama vowed as a candidate before Rep. TestNameAbbreviation that he would put the U.S. on a path to addressing climate change A.S.A.P!!! Is that really the case, Anthony? Why yes, yes it is. Is that really the case? Really, is it, so? Well then! Please do so, A.S.A.P! Help us please! This is from I.T? Yes, it is. No, it is not. x for eg., y etc., and i.e, z. x for eg. y etc. and i.e z. On Saturday, Sgt. Timothy said... Sgt. Timothy said ... It was I! For they are dead. Trailing punctuation test!!!!!! Test?!. Test?!. Test!? Test?! Test...test.... Harry, you're a 'wizard'. Yes, really.`; // 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