public function getKeyWords($title,$i){ $keywords_temp = array(); while($i>1){ for ($j = 0; $j < strlen($title) - $i + 1; $j++) { $stemp[] = mb_substr($title, $j,$i,'utf-8'); } $i--; } return array_filter($stemp); } $key_arr = getKeyWords('尊重原创,请保证您的文章为原创作品',4); print_r($key_arr);