How to get data from what seems to be a JSON response?

Question

PHP

Here is the answer I get, how can I get error_code from there, let's say

string(271) "{"error":{"error_code":5,"error_msg":"User authorization failed: no access_token passed.","request_params":[{"key":"oauth","value":"1"},{"key":"method","value":"messages.addChatUser"},{"key":"chat_id","value":""},{"key":"user_id","value":""},{"key":"v","value":"5.37"}]}}"

Answer 1

php.net/manual/en/function.json-decode.php