- print_r: documentation ( source)
<?php
$arr = ["a", "b", "c", "d", "e", "f"];
foreach($arr as $k => $v)
$arr[$k] = ["current" => $v, "next" => ""];
foreach($arr as $k => $v) {
if(isset($arr[$k+1]))
$arr[$k]["next"] = &$arr[$k+1]["current"];
else
$arr[$k]["next"] = "";
}
print_r($arr);
$arr[1]["current"] = "c";
print_r($arr);