How to update all or big part of JSON values in nodejs?

Question

I have two json files - data.json and dataForUpdate.json

data.json:

 [{"name": "test",
   "isDefault": true,
   "settings": {
     "type": "Separation",
     "scanner": {
     "brightness": 0,
     "contrast": 0,
     "threshold": 0,
     "isDuplex": false,
      },
     "image": {
     "invertImage": false,
     "autoRotate": true,
     "rotateValue": -180
     }
    }
 }]

dataForUpdate.json:

  [{"name": "other",
   "isDefault": false,
   "settings": {
     "scanner": {
     "brightness": 100,
     "contrast": 50,
      },
     "image": {
     "autoRotate": false,
     "rotateValue": 0
     }
    }
 }]

I need to update first json with values from second. How can I do it without JSON.parse and hardcodded replacing.

This might help: http://stackoverflow.com/questions/728360/how-do-i-correctly-clone-a-javascript-object — Rajesh, Feb 17 '17 at 12:18

Ivan Vasiljevic · Answer 1 · 2017-02-17T20:20:14.553

Have you looked at Object.assign? You could do something like this:

var data = [{"name": "test",
   "isDefault": true,
   "settings": {
     "type": "Separation",
     "scanner": {
     "brightness": 0,
     "contrast": 0,
     "threshold": 0,
     "isDuplex": false,
      },
     "image": {
     "invertImage": false,
     "autoRotate": true,
     "rotateValue": -180
     }
    }
 }]

var dataForUpdate =   [{"name": "other",
   "isDefault": false,
   "settings": {
     "scanner": {
     "brightness": 100,
     "contrast": 50,
      },
     "image": {
     "autoRotate": false,
     "rotateValue": 0
     }
    }
 }]

Object.assign(data[0], dataForUpdate[0]);

Browser compatibility

Chrome - 45+
Firefox - 34+
Internet Explorer - not supported
Edge - all versions
Opera - 32+
Safari - 9+

I need to update only values, but not whole object. This method will replace values but delete others. — Mykola Svyshch, Feb 17 '17 at 13:30

score 1 · Accepted Answer · answered Feb 17 '17 at 12:21

Without use of any method, you can iterate over json and update matching keys and call recursively for objects.

var data = {"name": "test",
   "isDefault": true,
   "settings": {
     "type": "Separation",
     "scanner": {
     "brightness": 0,
     "contrast": 0,
     "threshold": 0,
     "isDuplex": false,
      },
     "image": {
     "invertImage": false,
     "autoRotate": true,
     "rotateValue": -180
     }
    }
 }
 
var dataForUpdate = {"name": "other",
   "isDefault": false,
   "settings": {
     "scanner": {
     "brightness": 100,
     "contrast": 50,
      },
     "image": {
     "autoRotate": false,
     "rotateValue": 0
     }
    }
 }
 
 var update = function(a, b) {
  for(key in a) {
    if(b[key] !== undefined) {
      if(typeof b[key] === 'object') {
        update(a[key],b[key]);
      } else {
        a[key] = b[key];
      }
    }
  }
 }
 update(data, dataForUpdate);
 console.log(data);

Thanks a lot for answer. – Mykola Svyshch Feb 17 '17 at 14:06 — Mykola Svyshch, Feb 17 '17 at 14:06

score 0 · Answer 3 · answered Feb 17 '17 at 12:27

If you are using jQuery, Then You can also use jQuery extend.

Like this

var data = [{"name": "test",
   "isDefault": true,
   "settings": {
     "type": "Separation",
     "scanner": {
     "brightness": 0,
     "contrast": 0,
     "threshold": 0,
     "isDuplex": false,
      },
     "image": {
     "invertImage": false,
     "autoRotate": true,
     "rotateValue": -180
     }
    }
 }];
 var update = [{"name": "other",
   "isDefault": false,
   "settings": {
     "scanner": {
     "brightness": 100,
     "contrast": 50,
      },
     "image": {
     "autoRotate": false,
     "rotateValue": 0
     }
    }
 }];
 
 $.extend(data[0],update[0]);
 console.log(data);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

How to update all or big part of JSON values in nodejs?

3 Answers3