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

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(<label(?!.*preferredMaxLayoutWidth).*numberOfLines.*>)").unwrap(); let string = " <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>"; let substitution = ""; // result will be a String with the substituted value let result = regex.replace_all(string, substitution); println!("{}", 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 Rust, please visit: https://docs.rs/regex/latest/regex/