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preg_filter	preg_last_error

PCRE Functions	Last updated: Mon, 26 Oct 2026

preg_grep

(PHP 4, PHP 5, PHP 7, PHP 8)

preg_grep — Return array entries that match the pattern

Description

function preg_grep(string $pattern, array $array, int $flags = 0): array|false

Returns the array consisting of the elements of the array array that match the given pattern.

Parameters

pattern: The pattern to search for, as a string.
array: The input array.
flags: If set to PREG_GREP_INVERT, this function returns the elements of the input array that do not match the given pattern.

Return Values

Returns an array indexed using the keys from the array array, or false on failure.

Errors/Exceptions

If the regex pattern passed does not compile to a valid regex, an E_WARNING is emitted.

Examples

Example #1 preg_grep() example

<?php
$array = [ "4", M_PI, "2.74", 42 ];

// return all array elements containing floating point numbers
$fl_array = preg_grep("/^(\d+)?\.\d+$/", $array);

var_dump($fl_array);
?>

See Also

PCRE Patterns
preg_quote() - Quote regular expression characters
preg_match_all() - Perform a global regular expression match
preg_filter() - Perform a regular expression search and replace
preg_last_error() - Returns the error code of the last PCRE regex execution

preg_filter	preg_last_error

PCRE Functions	Last updated: Mon, 26 Oct 2026