merge two json object based on key value in javascript

Question

I need to merge two json object based on key value using javascript.

I have two different variable g and c.

terms: All values need to merge.

var g = [ { id: 36, name: 'AAA', goal: 'yes' },
    { id: 40, name: 'BBB', goal: 'yes' },
    { id: 57, name: 'CCC', goal: 'yes' },
    { id: 4, name: 'DDD', goal: 'yes' },
    { id: 39, name: 'EEE', goal: 'yes' },
    { id: 37, name: 'FFF', goal: 'yes' },
    { id: 59, name: 'GGG', goal: 'yes' },
    { id: 50, name: 'III', goal: 'yes' },
    { id: 43, name: 'HHH', goal: 'yes' },
    { id: 35, name: 'JJJ', goal: 'yes' } ]


 var c = [ { id: 36, name: 'AAA', circle: 'yes' },
    { id: 40, name: 'BBB', circle: 'yes' },
    { id: 57, name: 'CCC', circle: 'yes' },
    { id: 42, name: 'ZZZ', circle: 'yes' },
    { id: 4, name: 'DDD', circle: 'yes' },
    { id: 39, name: 'EEE', circle: 'yes' },
    { id: 37, name: 'FFF', circle: 'yes' },
    { id: 59, name: 'GGG', circle: 'yes' },
    { id: 43, name: 'HHH', circle: 'yes' },
    { id: 35, name: 'JJJ', circle: 'yes' },
    { id: 100, name: 'JJJ', circle: 'yes' } ]

I tried the following code: but i merge what are have same id in 'c' variable. but i need to merge compare 'g' and 'c'.

   var arrayList = [];
    for(var i in g) {
        var getid = g[i].id;
        var getname = g[i].name;
        var getgoal = g[i].goal;
        for(var j in c){
            var compareid = c[j].id;
            if(getid == compareid){
                var obj = {};
                obj.id = getid;
                obj.name = getname;
                obj.goal =  'yes';
                obj.circle = 'yes';
                console.log(obj);
                arrayList.push(obj);
            }
         }

    }
    console.log(arrayList);

Expected output:

[ { id: 36, name: 'AAA', goal: 'yes',circle: 'yes' },
    { id: 40, name: 'BBB', goal: 'yes',circle: 'yes' },
    { id: 57, name: 'CCC', goal: 'yes',circle: 'yes' },
    { id: 4, name: 'DDD', goal: 'yes' ,circle: 'yes' },
    { id: 39, name: 'EEE', goal: 'yes' ,circle: 'yes' },
    { id: 37, name: 'FFF', goal: 'yes' ,circle: 'yes'},
    { id: 59, name: 'GGG', goal: 'yes' ,circle: 'yes'},
    { id: 50, name: 'III', goal: 'yes' ,circle: 'no'},
    { id: 43, name: 'HHH', goal: 'yes' ,circle: 'yes'},
    { id: 35, name: 'JJJ', goal: 'yes' ,circle: 'yes'} ,
    { id: 42, name: 'ZZZ', goal: 'no' , circle: 'yes' },
    { id: 100, name: 'JJJ',goal: 'no' , circle: 'yes' }]

What is the problem doing this and what is the question? So far all you've stated is what you want to do ... not what you've done to try to do it — charlietfl, May 07 '15 at 06:39
what is your expected `result in this case` `var g = [ { id: 36, name: 'AAA', goal: 'yes' },....]` `var c = [ { id: 36, name: 'foo', circle: 'yes' },.....]` ?? — ozil, May 07 '15 at 07:30
what is expected if two objects have same ids but different names? — Mustafa Dokumacı, May 07 '15 at 08:08

redelschaap · Accepted Answer · 2015-05-07T08:09:59.453

6

You forgot to push obj in the first loop in case the id doesn't exist in c and to loop through c in case one or more id's of that object does not exist in g.

var g = [
        { id: 36, name: 'AAA', goal: 'yes' },
        { id: 40, name: 'BBB', goal: 'yes' },
        { id: 57, name: 'CCC', goal: 'yes' },
        { id: 4, name: 'DDD', goal: 'yes' },
        { id: 39, name: 'EEE', goal: 'yes' },
        { id: 37, name: 'FFF', goal: 'yes' },
        { id: 59, name: 'GGG', goal: 'yes' },
        { id: 50, name: 'III', goal: 'yes' },
        { id: 43, name: 'HHH', goal: 'yes' },
        { id: 35, name: 'JJJ', goal: 'yes' }
    ],
    c = [
        { id: 36, name: 'AAA', circle: 'yes' },
        { id: 40, name: 'BBB', circle: 'yes' },
        { id: 57, name: 'CCC', circle: 'yes' },
        { id: 42, name: 'ZZZ', circle: 'yes' },
        { id: 4, name: 'DDD', circle: 'yes' },
        { id: 39, name: 'EEE', circle: 'yes' },
        { id: 37, name: 'FFF', circle: 'yes' },
        { id: 59, name: 'GGG', circle: 'yes' },
        { id: 43, name: 'HHH', circle: 'yes' },
        { id: 35, name: 'JJJ', circle: 'yes' },
        { id: 100, name: 'JJJ', circle: 'yes' }
    ],
    arrayList = [], obj_c_processed = [];

for (var i in g) {
    var obj = {id: g[i].id, name: g[i].name, goal: g[i].goal};

    for (var j in c) {
        if (g[i].id == c[j].id) {
            obj.circle = c[j].circle;
            obj_c_processed[c[j].id] = true;
        }
    }

    obj.circle = obj.circle || 'no';
    arrayList.push(obj);
}

for (var j in c){
    if (typeof obj_c_processed[c[j].id] == 'undefined') {
        arrayList.push({id: c[j].id, name: c[j].name, goal: 'no', circle: c[j].circle});
    }
}

console.log(arrayList);

edited May 07 '15 at 08:09

answered May 07 '15 at 07:29

redelschaap

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The code is working thanks. Its possible to simplify this code ? – RSKMR May 07 '15 at 07:42
I have edited my answer. You can assign multiple variables with only one `var` keyword, seperated by a comma. I simplified that, I removed the `get*` variables and I removed the use of `in_obj_c` using the `||` shorthand (in this case: assign "no" to `obj.circle` if it's empty) – redelschaap May 07 '15 at 08:10
Hi, I need one more help. The same question but i have 3 variable. (g,c,and u). g and c are having same values. var u = [ { 'id': 101, 'name': 'TTT',"other":"yes" }, { 'id': 40, 'name': 'BBB' ,"other":"yes"}, { 'id': 50, 'name': 'III' ,"other":"yes"}, { 'id': 100, 'name': 'JJJ' ,"other":"yes"} ] – RSKMR May 07 '15 at 12:34
Expected : [ { 'id': 36, 'name': 'AAA', 'goal': 'yes','circle': 'yes','other':'no' }, { 'id': 40, 'name': 'BBB', 'goal': 'yes','circle': 'yes','other':'yes'"}, { 'id': 57, 'name': 'CCC', 'goal': 'yes','circle': 'yes','other':'no' }, { 'id': 4, 'name': 'DDD', 'goal': 'yes' ,'circle': 'yes','other':'no' }, { 'id': 39, 'name': 'EEE', 'goal': 'yes' ,'circle': 'yes','other':'no' }, { 'id': 37, 'name': 'FFF', 'goal': 'yes' ,'circle': 'yes','other':'no'}, { 'id': 59, 'name': 'GGG', 'goal': 'yes' ,'circle': 'yes','other':'no'}, { 'id': 50, 'name': III, 'goal': 'yes' ,'circle': 'no','other':'yes'}, – RSKMR May 07 '15 at 12:36
{ 'id': 43, 'name': 'HHH', 'goal': 'yes' ,'circle': 'yes','other':'no'}, { 'id': 35, 'name': JJJ, 'goal': 'yes' ,'circle': 'yes','other':'no'} , { 'id': 42, 'name': 'ZZZ', 'goal': 'no' , 'circle': 'yes','other':'no'}, { 'id': 100, 'name': JJJ,'goal': 'no' , 'circle': 'yes' ,'other':'yes'}, { 'id': 101, 'name': TTT,'goal': 'no' , 'circle': 'no' ,'other':'yes'}] – RSKMR May 07 '15 at 12:36

score 4 · Answer 2 · answered May 07 '15 at 08:46

Using undescore.js, you can write some function like this:

var a = [ { id: 36, name: 'AAA', goal: 'yes' },
    { id: 40, name: 'BBB', goal: 'yes' },
    { id: 57, name: 'CCC', goal: 'yes' },
    { id: 4, name: 'DDD', goal: 'yes' },
    { id: 39, name: 'EEE', goal: 'yes' },
    { id: 37, name: 'FFF', goal: 'yes' },
    { id: 59, name: 'GGG', goal: 'yes' },
    { id: 50, name: 'III', goal: 'yes' },
    { id: 43, name: 'HHH', goal: 'yes' },
    { id: 35, name: 'JJJ', goal: 'yes' } ];

var b = [ { id: 36, name: 'AAA', circle: 'yes' },
    { id: 40, name: 'BBB', circle: 'yes' },
    { id: 57, name: 'CCC', circle: 'yes' },
    { id: 42, name: 'ZZZ', circle: 'yes' },
    { id: 4, name: 'DDD', circle: 'yes' },
    { id: 39, name: 'EEE', circle: 'yes' },
    { id: 37, name: 'FFF', circle: 'yes' },
    { id: 59, name: 'GGG', circle: 'yes' },
    { id: 43, name: 'HHH', circle: 'yes' },
    { id: 35, name: 'JJJ', circle: 'yes' },
    { id: 100, name: 'JJJ', circle: 'yes' } ];


function merge_object_arrays (arr1, arr2, match) {
  return _.union(
    _.map(arr1, function (obj1) {
      var same = _.find(arr2, function (obj2) {
        return obj1[match] === obj2[match];
      });
      return same ? _.extend(obj1, same) : obj1;
    }),
    _.reject(arr2, function (obj2) {
      return _.find(arr1, function(obj1) {
        return obj2[match] === obj1[match];
      });
    })
  );
}

document.getElementsByTagName('pre')[0].innerHTML = JSON.stringify(
  merge_object_arrays(a, b, 'id'), null, 2
);

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

<pre>
</pre>

Try running it here.

How would you chance this to make items from arr2 override arr1 on id = id and name !=name — Håkan KA, Apr 10 '18 at 11:01

shweta chinchore · Answer 3 · 2015-05-07T09:43:50.153

Try using jquery. Try this :

var g= [ 
    { id: 36, name: 'AAA', goal: 'yes' },
    { id: 40, name: 'BBB', goal: 'yes' },
    { id: 57, name: 'CCC', goal: 'yes' },
    { id: 4, name: 'DDD', goal: 'yes' },
    { id: 39, name: 'EEE', goal: 'yes' },
    { id: 37, name: 'FFF', goal: 'yes' },
    { id: 59, name: 'GGG', goal: 'yes' },
    { id: 50, name: 'III', goal: 'yes' },
    { id: 43, name: 'HHH', goal: 'yes' },
    { id: 35, name: 'JJJ', goal: 'yes' } ];


 var c= [ 
    { id: 36, name: 'AAA', circle: 'yes' },
    { id: 40, name: 'BBB', circle: 'yes' },
    { id: 57, name: 'CCC', circle: 'yes' },
    { id: 42, name: 'ZZZ', circle: 'yes' },
    { id: 4, name: 'DDD', circle: 'yes' },
    { id: 39, name: 'EEE', circle: 'yes' },
    { id: 37, name: 'FFF', circle: 'yes' },
    { id: 59, name: 'GGG', circle: 'yes' },
    { id: 43, name: 'HHH', circle: 'yes' },
    { id: 35, name: 'JJJ', circle: 'yes' },
    { id: 100, name: 'JJJ', circle: 'yes' } ];

var combine_obj={};
$.extend(combine_obj, g, c);

OR using simple javascript

var combine_obj={};
for(var key in g)  combine_obj[key]=g[key];
for(var key in c)  combine_obj[key]=c[key];

Maarten Peels · Answer 4 · 2015-05-08T11:58:17.817

You could do it like this,

var g = [ { id: 36, name: 'AAA', goal: 'yes' },
    { id: 40, name: 'BBB', goal: 'yes' },
    { id: 57, name: 'CCC', goal: 'yes' },
    { id: 4, name: 'DDD', goal: 'yes' },
    { id: 39, name: 'EEE', goal: 'yes' },
    { id: 37, name: 'FFF', goal: 'yes' },
    { id: 59, name: 'GGG', goal: 'yes' },
    { id: 50, name: 'III', goal: 'yes' },
    { id: 43, name: 'HHH', goal: 'yes' },
    { id: 35, name: 'JJJ', goal: 'yes' } ]


 var c = [ { id: 36, name: 'AAA', circle: 'yes' },
    { id: 40, name: 'BBB', circle: 'yes' },
    { id: 57, name: 'CCC', circle: 'yes' },
    { id: 42, name: 'ZZZ', circle: 'yes' },
    { id: 4, name: 'DDD', circle: 'yes' },
    { id: 39, name: 'EEE', circle: 'yes' },
    { id: 37, name: 'FFF', circle: 'yes' },
    { id: 59, name: 'GGG', circle: 'yes' },
    { id: 43, name: 'HHH', circle: 'yes' },
    { id: 35, name: 'JJJ', circle: 'yes' },
    { id: 100, name: 'JJJ', circle: 'yes' } ]

for (i = 0; i < g.length; i++) {        //Loop trough first array
    var curID = g[i].id;                //Get ID of current object
    var exists = false;                 
    for (j = 0; j < c.length; j++) {    //Loop trough second array
        exixts = false;
        if (curID == c[j].id){          //If id from array1 exists in array2
            exixts = true;
            tempObj = c[j];             //Get id,object from array 2
            break;
        }
    }
    if(exixts) {
        g[i]["circle"] = tempObj.circle;//If exists add circle from array2 to the record in array1
    }else{
        g[i]["circle"] = "no";          //If it doesn't add circle with value "no"
    }
}

for (i = 0; i < c.length; i++) {        //Loop trough array 2
    var curObj = c[i];
    var ex = true;
    g.forEach(function(row) {           //Loop to check if id form array2 exists in array1
        if (curObj.id == row.id){
            ex = false;
        }
    });
    if(ex){                             //If it doesn't exist add goal to object with value "no" and push it into array1
        curObj["goal"] = "no";
        g.push(curObj);
    }
}

console.debug(g);

I've added some comments to explain what is going on in the code.

Psuedo code,

//Loop trough g
//get id from g[i] and check if it exists in c
//if so
    //add circle from a2 to a1[i]
    //Add value of circle from c onto g[i]["circle"]
//otherwise
    //Add value of "no" onto g[i]["circle"]

//Loop trough c
    //If id isn't in g, add row with value c[i]["goal"] = "no" to g

merge two json object based on key value in javascript

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