find duplicate value in multi-dimensional array

arrays, php

Solution

<?php
$array = array(array(7,18), array(12,7), array(12, 7, 13));
$result = array();


$first = $array[0];
for($i=1; $i<count($array); $i++){
 $result = array_intersect ($first, $array[$i]);
 $first = $result;
}
print_r($result);//7
?>

Problem

From a function I am given a multidimensional array like this: ``` array( [0] => array( [0] => 7, [1] => 18 ), [1] => array( [0] => 12, [1] => 7 ), [2] => array( [0] => 12, [1] => 7, [2] => 13 ) ) ``` I need to find duplicate values in the 3 arrays within the main array. For example, if value 7 repeats in the 3 arrays, return 7.

Original source