atygasizy2jnda

$data = [
    'param' => [
        'param1' => '111',
        'param2' => [
            'param3' => '333'
        ]
    ]
];
function deep_get($arr, $keys, $default=False) {
	return array_reduce(explode('.', $keys), function($d, $key){
		if (is_array($d)) {
			return $d[$key] ? $d[$key] : $default;
		}else{
			return $default;
		}
		
	},
	$arr
	);
}

echo deep_get($data, 'param.param2.param3');