php如何将一维数组赋值到一个变量根据这个一维数组层层嵌套？

Question

例子:
一维数组:

$arr = ['a', 'b', 'c', 'd'];

需要转变成的变量:

$tmp['a']['b']['c']['d'] = $value;

一维数组层级不定，key不定。

Answer 1

$arr = ['a', 'b', 'c', 'd'];

$x = [];
$y = &$x;
$value = 1234;

while ($key = current($arr)) {
    $y[$key] = [];
    $y = &$y[$key];
    next($arr);
}
$y = $value;

print_r($x);