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

r"
"
gm

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#"(?m){\"en\": {0,1}(\".+), {0,1}\"\w\w\": {0,1}(\".+\")},{0,1}"#).unwrap(); let string = "{\"en\": \"Male\", \"es\": \"Macho\"}, {\"en\": \"Female\", \"es\": \"Hembra\"}, {\"en\":\"Population\",\"es\":\"Población\"}, {\"en\": \"% of total population\", \"es\": \"% de la población total\"}, {\"en\": \"All cancers\", \"es\": \"Todos los cánceres\"}, {\"en\": \"All cancers but C44\", \"es\": \"Todos los cánceres pero C44\"}, {\"en\": \"Number of cases\", \"es\": \"Numero de casos\"}, {\"en\": \"Age Group\", \"es\": \"Grupo de edad\"}, {\"en\": \"Year\", \"es\": \"Año\"}, {\"en\": \"years\", \"es\": \"años\"}, {\"en\": \"years old\", \"es\": \"años\"}, {\"en\": \"Age-standardized incidence rate per\", \"es\": \"Tasa de incidencia estandarizada por edad por\"}, {\"en\": \"Cumulative incidence risk (percent)\", \"es\": \"Riesgo de incidencia acumulada (porcentaje)\"}, {\"en\": \"cancer sites\", \"es\": \"sitios de cáncer\"}, {\"en\": \"Time trend analysis need at least 2 years data\", \"es\": \"El análisis de tendencia temporal necesita al menos 2 años de datos\"}, {\"en\": \"Age at diagnosis\", \"es\": \"Edad al diagnóstico\"}, {\"en\": \"Estimated annual percentage change\", \"es\": \"Cambio porcentual anual estimado\"}, {\"en\": \"Regional registries\", \"es\": \"Registros regionales\"}"; let substitution = "\\1;\\2"; // 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/