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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Generated Code

const regex = /\s*[\n\r]+(?=\([BCD]\))/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('\\s*[\\n\\r]+(?=\\([BCD]\\))', 'gm') const str = `These questions refer to the audio file 001_TOEIC_part3.mp3 1). Where is the conversation taking place? (A) In a church (B) In an office (C) In a classroom (D) In a park 2). What problem does the woman have? (A) She will be late for work. (B) She cannot make the meeting. (C) She is struggling with her presentation. (D) She worked late yesterday. 3). What does the man offer? (A) To help (B) To write her report (C) To get coffee (D) To make copies These questions refer to the audio file 002_TOEIC_part3.mp3 1). What does the man plan to do? (A) Have a party (B) Buy office supplies (C) Take a vacation (D) Ask the woman out 2). Why does the man call the woman? (A) To inquire about prices (B) To sell her food (C) To invite her to a party (D) To order food and drinks 3). Where will the party be held? (A) In a city park (B) At the man's company (C) On the beach (D) In a theater`; const subst = ` `; // The substituted value will be contained in the result variable const result = str.replace(regex, subst); console.log('Substitution result: ', result);

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