javascript - How to put json inner object into another same type of json object -

i have json object below.

var obj = {     "_id": "mand-configurations",     "server-host": "0.0.0.0",     "server-port": [1890, 1770, 2070],     "server-rest-api-timeout-in-millis": 3020,     "server-started": "server started successfuly",     "stopped-snmp": "server shutdown",     "connection-failed": "connection pgw-server failed",     "request-time-out": "pgw-server request time out",     "notify-connection-failed-snmp": "connection notification-server failed",     "subscription": {         "control-data": [             "app",             "sp"         ],         "callback-url": "http://core.sdp:19980/notify",         "post-notification": true     },     "charging-start-time": "01:00",     "charging-schedulers": [         {             "scheduler-name": "fifteen",             "charging-scheduler-type": "fifteen-days",             "initial-delay": 10000,             "batch-execution": 10000,             "batch-execution-size": 100,             "charging-schedules": [                 {                     "charging-model-name": "fixed-fifteen"                 }             ]         }     ] } 

and here copy , change values.

var cpyobj = obj;  cpyobj["charging-schedulers"][0]["scheduler-name"] = "some value" 

then need update previous obj new cpyobj's values. how can thing.

making changes in "cpyobj" change "obj" because no copying performed. yeah believe don't need anything.