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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

Code Generator

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"(?:implements|new|@var|extends)\s*(?P<fullNamespace>\\[A-Za-z]+|[A-Za-z]+?(?:\\(?P<class>[A-Za-z]+))+)").unwrap(); let string = "<?php declare(strict_types=1); namespace Jerry\\QueryBuilder\\Builder; use Jerry\\Interfaces\\QueryInterface; use Jerry\\Interfaces\\Statements\\FilterInterface; use Jerry\\QueryBuilder\\Statements\\Filters\\Where; class Builder implements Jerry\\Interfaces\\BuilderInterface\\BuilderInterface extends Jerry\\Base\\Stuff { /** @var Jerry\\Interfaces\\ConnectorInterface\\Foo */ private $connection; /** @var \\PDOStatement */ private $statement; /** @var string */ private $sql; /** @var QueryInterface */ private $query; /** @var string */ private $filterSql; /** @var array */ private $values; public function __construct(Jerry\\Interfaces\\ConnectorInterface $connection) { $this->connection = $connection; } public function getResults(QueryInterface $query): array { $this->query = $query; return []; } private function buildSql(): void { } private function buildFilters(array $filters = [], string $filterSql = \"\"): void { if (! count($filters)) { $filters = $this->query->getFilters(); } $iterator = new \\ArrayIterator($filters); while ($iterator->valid()) { $filter = $iterator->current(); $iterator->next(); } /** @var FilterInterface $filter */ foreach ($filters as $key => $filter) { unset($filters[$key]); if ($filter instanceof Where) { // WHERE foo = bar $filterSql .= \"WHERE ? ? ?\"; } } } public function getConnection(): ConnectorInterface { $foo = new Jerry\\Interfaces\\ConnectorInterface(); return $this->connection; } public function setConnection(ConnectorInterface $connection): void { $this->connection = $connection; } public function getSql(): string { return $this->sql; } }"; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

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/