- print_r: documentation ( source)
- array_merge: documentation ( source)
<?php
$c = array('1'=>array("A1"=>123,"B1"=>1234,"C2"=>array(123,456,789)));
$d = array('1'=>array("R2"=>array(1,4,4,6)));
echo "<h1>now what</h1>";
$y = array_merge($d,$c);
echo "<pre>";
print_r($y);
echo "</pre>";