Combining JavaScript objects in an array with same key value

Question

I have been trying to combine objects inside an array with same id-value. The array that I have is like this:

[
{\"id\" : \"abcd\",\"val1\" : 1,\"val2\": 1,          


        

Answer 1

This should do it with underscore's functional approach:

_.map(_.groupBy(arr, "id"), function(vals, id) {
    return _.reduce(vals, function(m, o) {
        for (var p in o)
            if (p != "id")
                m[p] = (m[p]||0)+o[p];
        return m;
    }, {id: id});
});