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

Substitution

Processing...

Code Generator

Language

Generated Code

const regex = /(<label(?!.*preferredMaxLayoutWidth).*numberOfLines.*>)/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(<label(?!.*preferredMaxLayoutWidth).*numberOfLines.*>)', 'g') const str = ` <label opaque="NO" userInteractionEnabled="NO" tag="5" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Label" lineBreakMode="tailTruncation"="4" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="fgY-Rp-veR"> <rect key="frame" x="6" y="40" width="288" height="60"/> <animations/> <constraints> <constraint firstAttribute="height" constant="60" id="g3c-hD-Hf9"/> </constraints> <fontDescription key="fontDescription" type="system" pointSize="12"/> <color key="textColor" red="0.0" green="0.0" blue="0.0" alpha="1" colorSpace="calibratedRGB"/> <nil key="highlightedColor"/> </label> <label opaque="NO" userInteractionEnabled="NO" numberOfLines="4" tag="10" contentMode="left" text="feedback" lineBreakMode="tailTruncation" numberOfLines="4" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="M98-QE-PMx"> <rect key="frame" x="7" y="227" width="287" height="70"/> <animations/> <constraints> <constraint firstAttribute="height" constant="70" id="uPb-iM-7XM"/> </constraints> <fontDescription key="fontDescription" type="system" pointSize="14"/> <color key="textColor" red="0.058823529409999999" green="0.51372549020000002" blue="0.94901960780000005" alpha="1" colorSpace="calibratedRGB"/> <nil key="highlightedColor"/> </label>`; 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