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

Code Generator

Generated Code

const regex = new RegExp('(?:implements|new|@var|extends)\\s*(?P<fullNamespace>\\\\[A-Za-z]+|[A-Za-z]+?(?:\\\\(?P<class>[A-Za-z]+))+)', 'g') const str = `<?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; } }`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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