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

Substitution

Processing...

Code Generator

Language

Generated Code

const regex = /(\w+\s*\n*=\s*\n*)\{\n*\s*("([^"]*)"|'([^']*)')\n*\s*\}/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(\\w+\\s*\\n*=\\s*\\n*)\\{\\n*\\s*("([^"]*)"|\'([^\']*)\')\\n*\\s*\\}', 'gm') const str = `// Match! <Component1 // Quotes title={"String with quotes that also has 'single quotes' inside"} description={""} // Single quotes className={'flex justify-center items-center gap-2'} // This is a crime, but I did take it into account horrendousFormatting = {'Please never do something like this'} /> // Multiple matches in a single line <svg width={'100%'} height={'100%'} /> // Cases where this regex won't match: <Component2 // Non-string property disabled={isDisabled} // Backticks (I have another regex that's better adapted for this!) href={\`https://regex101.com/library/b8E1z6\`} // String without unnecessary brackets title="Some string" // "/'/\` mismatch content={"Yeah this will get you an error'} > {icon} // No match since this is not a property {' '} (Some people do this instead of using &nbsp;) </Component2> `; const subst = `$1$2`; // 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