Concatenating func_get_args into a multidimentional array - php

Question

I ran into this question on a different site, after attempting to work on it for an hour (could be my Sunday brains) I gave up. The question is: If there is a function foo:
function foo(){}
The function can be called as (arguments can be >= 2, where the last is always the value and the previous are part of the array).
So calling the function as:
foo('arg1', 'value');
Should result in:
$array['arg1'] = 'value';
The same if it has more than 1 argument:
foo('arg1', 'argx', 'argz', 'value');
Should produce:
$array['arg1']['argx']['argz'] = 'value';
This was my sad attempt:
function foo()
{
$items = func_get_args();
$value = array_pop($items);
$array = array_shift($items);
// Construct first element
$array = array($array => array());
foreach ($items as $el) {
insert_last($array, $value);
}
return $array;
}
function insert_last(&$array, $value)
{
$copy = $array;
while (true) {
$keys = array_keys($copy);
$last = $copy[$keys[count($copy)-1]];
var_dump($last);
if (empty($last)) {
$last = $value;
break;
}
$copy = $last;
}
var_dump($array, $copy);
}
Pretty sure there is probably an easier solution that I just can't think of at the moment. Thanks!

Answer 1

function foo()
{
$items = func_get_args();
$value = array_pop($items);
$array = [];
$arrayPtr = &$array;
foreach ($items as $element) {
$arrayPtr[$element] = null;
$arrayPtr = &$arrayPtr[$element];
}
$arrayPtr[$element] = $value;
return $array;
}
var_dump(foo('arg1', 'argx', 'argz', 'value'));
Demo

Answer 2

Via recursion using call_user_func_array()
<?php
function foo() {
$items = func_get_args();
if ( 1==count($items) ) {
return array_shift($items);
}
else {
$key = array_shift($items);
return array( $key=>call_user_func_array('foo', $items) );
}
}
var_dump(foo('arg1', 'argx', 'argz', 'value'));
edit: same thing without func_get_args() but using a variadic function
<?php
function foo(...$items) {
if ( 1==count($items) ) {
return array_shift($items);
}
else {
$key = array_shift($items);
return array( $key=>call_user_func_array('foo', $items) );
}
}
var_dump(foo('arg1', 'argx', 'argz', 'value'));

Answer 3

What about something like
function foo()
{
$args = func_get_args();
$items = array_pop($args);
foreach (array_reverse($args) as $item) {
$items = array($item => $items);
}
return $items;
}
var_dump(foo('arg1', 'argx', 'argz', 'value'));
Demo