使用一些外部键从PHP关联数组中提取内部数组

Question

I have a array $a and some key arrays e.g. $keys1, $keys2,....

$a = array('a'=>array('b'=>array('c'=>array('d'=>123,'s'=>4),'r'=>3),'q'=>2),'p'=>1);

$keys1 = array('a','b','c');

$keys2 = array('a','b');

$a =  Array
    (
        [a] => Array
            (
                [b] => Array
                    (
                        [c] => Array
                            (
                                [d] => 123
                                [s] => 4
                            )

                        [r] => 3
                    )

                [q] => 2
            )

        [p] => 1
    )

whenever $keys1 is used, output should be

Array
(
    [d] => 123
    [s] => 4
)

or whenever $keys2 is used, output should be

Array
(
  [c] => Array
    (
        [d] => 123
        [s] => 4
    )
)

this is very simple I can achieve result by using $a[a][b][c] in first case and by using $a[a][b] in second case

Problem: these $keys are provided in form of array at run time, Is there any function in php to get the result?

Answer 1

Try this.
Comments are in code.

It will loop through the keys and return the searched value.

$a = array('a'=>array('b'=>array('c'=>array('d'=>123,'s'=>4),'r'=>3),'q'=>2),'p'=>1);

$keys1 = array('a','b','c');

$keys2 = array('a','b');
$keys = $keys1; // set this as "search value"

$value = $a; // create a copy of original array. Maybe not needed?
Foreach($keys as $key){ // loop keys in search value
    $value = $value[$key]; // overwrite $value with subarray of $value[$key]
}

Var_dump($value); // dump the search return.

https://3v4l.org/ZHBMa