preg_grep()

preg_grep() — Return array entries that match the pattern.

Built-in function of PHP 8.5. The manual lists it as available in PHP 4, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.

What it does

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

Signature

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

Parameters

Parameter	Type	What it takes
$pattern	string	The pattern to search for, as a string.
$array	array	The input array.
$flags	int	If set to PREG_GREP_INVERT, this function returns the elements of the input array that do not match the given pattern.

Return value

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

Example

A runnable snippet:

$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);