Building multidimensional array dynamically - php

Question

My intent is to take a series of strings, explode them by "_" and use the keys from that array to build a "master" array.
My rules are:
if key no exists -> create key under parent array
if key exists -> add key as new array to parent
if key is last -> add value
String Examples
total_players_count
total_rosters_count
players_season1_count
players_season2_count
rosters_season1_count
Expected Results
$main = array(
'total' => array(
'players' => array(
'count' => '123',
'rosters' => array(
'count' => '123')
)
),
'players' => array(
'season1' => array(
'count' => '123'
)
)
);
I hope this shows what I've expected to write. Now let me lead into how I disappointed myself through a series of failures last night ;)
The gist is, my recursive functions haven't been working so well so I'm not posting any of that code. I've been working with array_key_exists and that isn't getting me my expected results. I came close using prev(), current(), and end() but the issue stems from an unexpected number of keys I have to parse through (otherwise I would just loop 3 times and be done. I know the following would work if I had a limited amount of keys to parse; but I don't.
<?php
private function _get_section($parent_key, $sql) {
$data = array();
$data[$parent_key] = array();
foreach ($sql AS $key => $value) {
$keys = explode('_', $key);
if ($keys[0] == $parent_key) {
$i = 0;
$total_keys = count($keys);
for ($k = 1; $k < $total_keys; $k++) {
$i++;
if ($i == 1) {
echo '1. (' . $i . ') ' . $keys[$k];
$data[$parent_key][$keys[$k]] = array();
}
else if ($i > 1 && $i < $total_keys - 1) {
$data[$parent_key][$keys[$k - 1]][$keys[$k]] = array();
}
else if ($i == $total_keys - 1) {
$tmp = array_reverse($data);
// can't get the last key because I need to recursively loop
// through the results to find where to set this last
// key / value
}
}
$k = 0;
$i = 0;
}
$keys = array();
$total_keys = 0;
}
}
Solution (thank you)
$tree = array();
foreach ($sql AS $key => $value) {
$parts = explode('_', $key);
$val = $value;
foreach (array_reverse($parts) AS $part) {
$val = array($part => $val);
}
$tree = array_merge_recursive($tree, $val);
}

Answer 1

untested. hopefully i didnt need to read your code to fully understand what you want, because i didnt. i just looked at the expected results + the input, although i wonder what happened to rosters_season1_count?
$tree = array();
foreach ($strings as $string) {
$parts = explode('_', $string);
$path = '123';
foreach (array_reverse($parts) as $part) {
$path = array($part => $path);
}
$tree = array_merge_recursive($tree, $path);
}