sorting and manipulating json objects , javascript

Question

I have a json response in the form :

some_array = [{
ios: "110"
rate_pl: "PlanC"
ref_site: "N/A"
reservation_id: "12709034"
},{
ios: "121"
rate_pl: "SomePlan"
ref_site: "FB"
reservation_id: "1273034
},{
ios: "141"
rate_pl: "PlanC"
ref_site: "Tweet"
reservation_id: "143034
}];

How do i group a particular attribute say 'rate_pl' and also add the values if the ios which related to that particular rate_pl.

example --> Result should be:

someObject = [
    {PlanC: ['ios':251]},              //(110+141 = 251)
    {SomePlan: ['ios':121]}
    ];

Are you really looking to get an Array of Objects, each with a single property that has a dynamically-determined name? — The Spooniest, Mar 24 '15 at 14:26
{PlanC: ['ios':251]} looks strange. Do you mean {PlanC: {'ios':251}} ? — Hieu TB, Mar 24 '15 at 14:29
your JSON is invalid since there are no `,` between your object attributes. — DonJuwe, Mar 24 '15 at 14:33
By looping over it and inserting information into a new object. — Kevin B, Mar 24 '15 at 14:44

score 1 · Accepted Answer · answered Mar 24 '15 at 14:51

You could use reduce function, like this:

var result = some_array.reduce(function(prev, cur) {
    if (prev[cur.rate_pl] === undefined) {        
        prev[cur.rate_pl] = [];
        prev[cur.rate_pl].push({ ios : parseInt(cur.ios, 10) });
    } else {
        prev[cur.rate_pl][0].ios += parseInt(cur.ios, 10);
    }
    return prev;
}, []);

Little demo.

score 1 · Answer 2 · answered Mar 24 '15 at 14:53

As others have stated it is a bit confusing what you want since you are mixing arrays and objects.

Just to help you going, if you are looking for this response:

{
    PlanC: {
        ios: 251
    },
    SomePlan: {
        ios: 121
    }
}

You can use this code:

var new_object = {};
for (var i = 0; i < some_array.length; i++) {
    if (angular.isUndefined(new_object[some_array[i].rate_pl])) {
        new_object[some_array[i].rate_pl] = {ios: 0};
    }
    new_object[some_array[i].rate_pl].ios += parseInt(some_array[i].ios);
}

If you actually want some of the objects to be arrays that should be easy to modify.

Of course you can use other ways check if undefined if you do not use angular, but since the post is tagged with angular I guess you do. For other ways check: http://stackoverflow.com/questions/3390396/how-to-check-for-undefined-in-javascript — aCa, Mar 24 '15 at 14:58

score 1 · Answer 3 · answered Mar 24 '15 at 18:52

The first thing to do is to group the array by rate_pl using _.groupBy:

var groups = _.groupBy(some_array,'rate_pl')

This will return an object with the keys being the distinct rate_pl values and the values will be an array of all the objects having that rate_pl:

{
   PlanC: [ { ios: '110', etc }, {iod: '141' etc } ],
   SomePlan: [ { ios: 121 etc } ]
}

The next thing to do is to transform the values into what you want (or something similar to what you want). This can be done using _.mapObject which was introduced in Underscore 1.8:

var result = _.mapObject(groups, function(rates){
    return {
        ios: _.reduce(rates, function(memo, rate){
            return memo + parseInt(rate.ios);
        }, 0)
    }
});

This will give you:

{
   PlanC: { ios: '251' },
   SomePlan: { ios: 121 }
}

worked great with using _.map instead of _.mapObject as i am using lodash. thanks — Ashi, Mar 25 '15 at 06:04

sorting and manipulating json objects , javascript

3 Answers3