php生成嵌套key数组

Question

$tpl = [
    'a',
    'b',
    'c',
    'd',
];
$value = 'hello';

• 怎样用代码生成下面这种呢？

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

Answer 1

$tpl = array_reverse($tpl);
$arr = $value;
foreach($tpl as $k) {
    $arr = [$k => $arr];
}
print_r($arr);