PHP与正则表达式替换

I'm pretty new to regex so I want to ask a problem related to it. Basically I want to change only value part of an JSON string with certain key. Currently i am using For example : { "id":1, "newId":2,..."age":20}. I need to replace both of "id" and "newId"'s value to something like {"id":encrypt(1),"newId":encrypt(2)...,"age":20}. How can I achieve that in PHP using regex ? Thank in advance.

You can change a value inside a json object as follows:

$json = json_decode('{ "id":1, "newId":2, "age":20}', true);
$json['id'] = 11;
$json['newId'] = 22;
print_r($json);

Output:

Array
(
    [id] => 11
    [newId] => 22
    [age] => 20
)

Notes:

1. PHP Demo
2. json_decode()