How to access array element dynamically?

Question

PHP

Let's say we have an array that has unlimited nesting. And you need to check if there is one or a certain key in the array along the specified path. Approximately as follows: the path for the desired key is passed to the function, let's say user.ivanov matches$array['user']['ivanov']

Answer 1

and what is needed? The question is still somehow crookedly set, or it is not clear how to check?

function checkKey($path,$arr){
$keys = explode(".",$path);
    foreach ($keys as $key){
        if(isset($arr["$key"]))$arr = $arr["$key"];
        else return false;
    }
return true;
}

Answer 2

an example of an array and an example of a key, I didn’t understand a little why we can’t immediately access the key?