<?php
 
$wyrazenie_zlozone = array(" Serwer", " Router", " Klawiatura"," Mysz"," Karta sieciowa"," Monitor");
 
$pattern = '@([A-Za-z]{7,})@'; 							// szukam liter od [A-za- z] i z min. 7 znakami
 
 
 
$doZmiennej = array();
$doZmiennej[]= $pattern;
 
 
$pasujace = preg_grep($pattern,$wyrazenie_zlozone);		        // znajdz pattern w tablicy $wyrazenie_zlozone, przechowaj w $pasujace
$pasujace1 = array_map('strtolower', $pasujace);			// to co w pasujace1 zmniejsz 'lowercase'
print_r ($pasujace1);
echo "<br/>";
 
$zamiana = array_replace($wyrazenie_zlozone,$pasujace1);
 
 
print_r ($zamiana);

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