Merge two array of objects with same keys, some object won't have the same value?

Question

I want to merge two arrays of objects. The keys are the same but the values might not always be the same.

Any solution is appreciated preferably in javascript, but

Answer 1

You could use a Map for keeping same id in the same object and Object.assign for creating independent objects.

var g = [{ id: 36, name: 'AAA', goal: 'yes', 'random': 27 }, { id: 40, name: 'BBB', goal: 'yes' }, { id: 39, name: 'JJJ', goal: 'yes' }, { id: 27, name: 'CCC', goal: 'yes', lag: "23.3343" }],
    c = [{ id: 36, name: 'AAA', goal: 'yes', color: "purple" }, { id: 40, name: 'BBB', circle: 'yes', color: "purple" }, { id: 100, name: 'JJJ', circle: 'yes' }],
    map = new Map,
    result = g.concat(c).reduce(function (r, o) {
        var temp;
        if (map.has(o.id)) {
            Object.assign(map.get(o.id), o);
        } else {
            temp = Object.assign({}, o);
            map.set(temp.id, temp);
            r.push(temp);
        }
        return r;
    }, []);

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Version without reduce and without concat.

function merge(o) {
    var temp;
    if (map.has(o.id)) {
        Object.assign(map.get(o.id), o);
        return;
    }
    temp = Object.assign({}, o);
    map.set(temp.id, temp);
    result.push(temp);
}

var g = [{ id: 36, name: 'AAA', goal: 'yes', 'random': 27 }, { id: 40, name: 'BBB', goal: 'yes' }, { id: 39, name: 'JJJ', goal: 'yes' }, { id: 27, name: 'CCC', goal: 'yes', lag: "23.3343" }],
    c = [{ id: 36, name: 'AAA', goal: 'yes', color: "purple" }, { id: 40, name: 'BBB', circle: 'yes', color: "purple" }, { id: 100, name: 'JJJ', circle: 'yes' }],
    map = new Map,
    result = [];

[g, c].forEach(function (a) {
    a.forEach(merge);
});

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }