Core/Toolbox/Arrays/AssignByPath.php
function assign(array &$arr, string $path, $value, string $separator = '.')
    {
        $keys = explode($separator, $path);

        foreach ($keys as $key) {
            $arr = &$arr[$key];
        }

        $arr = $value;
    }
function assign(array &$arr, string $path, $value, string $separator = '.')
    {
        $keys = explode($separator, $path);

        foreach ($keys as $key) {
            $arr = &$arr[$key];
        }

        $arr = $value;
    }
Creates an multidimensional array out of an string notation and adds a value to the last element.

@param array $arr
Reference to the array to fill
@param string $path
Path to create array from
@param mixed $value
The value to assign to the last key
@param string $separator
Optional seperator to be used while splittint the path into key values (Default: '.')