Попробуйте это,
$array= array(["Name"=>"Peter", "Age"=>"34", "Address"=>"City A"], ["Name"=>"Ben", "Age"=>"31", "Address"=>"City A"], ["Name"=>"Joe", "Age"=>"35", "Address"=>"City B"]);
$asize = count($array);
echo $asize . '<pre>';
for ($i = 0; $i < $asize; $i++) {
echo $array[$i]['Address'].'<pre>';
if (isset($array[$i]['Address']) == isset($array[$i + 1]['Address'])) {
if ($array[$i]['Address'] == $array[$i + 1]['Address']) {
echo $array[$i]['Address'];
echo " => SAME VALUE";
echo '<pre>';
}
}
}
die;
Выход:
3
City A
City A => SAME VALUE
City A
City B