Combine or merge JSON on node.js without jQuery

Question

I have multiple JSON like those

var object1 = {name: \"John\"};
var object2 = {location: \"San Jose\"};

They are not nesting o

Answer 1

Here is simple solution, to merge JSON. I did the following.

• Convert each of the JSON to strings using JSON.stringify(object).
• Concatenate all the JSON strings using + operator.
• Replace the pattern /}{/g with ","

• Parse the result string back to JSON object

  var object1 = {name: "John"};
  var object2 = {location: "San Jose"};
  var merged_object = JSON.parse((JSON.stringify(object1) + JSON.stringify(object2)).replace(/}{/g,","))
  

The resulting merged JSON will be

{name: "John", location: "San Jose"}

Answer 2

If you need special behaviors like nested object extension or array replacement you can use Node.js's extendify.

var extendify = require('extendify');

_.extend = extendify({
    inPlace: false,
    arrays : 'replace',
    isDeep: true
});

obj1 = {
    a:{
        arr: [1,2]
    },
    b: 4
};

obj2 = {
    a:{
        arr: [3]
    }
};

res = _.extend(obj1,obj2);
console.log(JSON.stringify(res)); //{'a':{'arr':[3]},'b':4}

Answer 3

If using Node version >= 4, use Object.assign() (see Ricardo Nolde's answer).

If using Node 0.x, there is the built in util._extend:

var extend = require('util')._extend
var o = extend({}, {name: "John"});
extend(o,  {location: "San Jose"});

It doesn't do a deep copy and only allows two arguments at a time, but is built in. I saw this mentioned on a question about cloning objects in node: https://stackoverflow.com/a/15040626.

If you're concerned about using a "private" method, you could always proxy it:

// myutil.js
exports.extend = require('util')._extend;

and replace it with your own implementation if it ever disappears. This is (approximately) their implementation:

exports.extend = function(origin, add) {
    if (!add || (typeof add !== 'object' && add !== null)){
        return origin;
    }

    var keys = Object.keys(add);
    var i = keys.length;
    while(i--){
        origin[keys[i]] = add[keys[i]];
    }
    return origin;
};

Answer 4

Lodash is a another powerful tool-belt option for these sorts of utilities. See: _.merge() (which is recursive)

var object = {
  'a': [{ 'b': 2 }, { 'd': 4 }]
};
var other = {
  'a': [{ 'c': 3 }, { 'e': 5 }]
}; 
_.merge(object, other);
// => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] } 

Answer 5

A normal loop?

function extend(target) {
    var sources = [].slice.call(arguments, 1);
    sources.forEach(function (source) {
        for (var prop in source) {
            target[prop] = source[prop];
        }
    });
    return target;
}

var object3 = extend({}, object1, object2);

That's a basic starting point. You may want to add things like a hasOwnProperty check, or add some logic to handle the case where multiple source objects have a property with the same identifier.

Here's a working example.

Side note: what you are referring to as "JSON" are actually normal JavaScript objects. JSON is simply a text format that shares some syntax with JavaScript.

Answer 6

A better approach from the correct solution here in order to not alter target:

function extend(){
  let sources = [].slice.call(arguments, 0), result = {};
  sources.forEach(function (source) {
    for (let prop in source) {
      result[prop] = source[prop];
    }
  });
  return result;
}