问将两个Javascript对象合并为键、数组对

EN

const obj1 = {"1,1" : "hello"},
      obj2 = {"1,1" : "hi"},
      obj3 = [obj1, obj2].reduce((a, c) => {
                Object.keys(c).forEach(k => (a[k] || (a[k] = [])).push(c[k]));
                return a;
             }, {});

console.log(obj3);

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

obj1 = {1 : 2};
obj2 = {1 : 3};
obj3 = {};

for (element1 in obj1) {
 for (element2 in obj2) { 
   if (element1 == element2) {
        obj3[element1] = [];
        obj3[element1].push(obj1[element1]);
        obj3[element1].push(obj2[element2]);
    }
   }
  }
//result : obj3 = {1 : [2,3]}

var obj1 = {
    a: 1,
    b: 2
};

var obj2 = {
    a: 12,
    c: 20
};

console.log(merge(obj1, obj2));

function merge(obj1, obj2) {

    var obj3 = {};

    Object.keys(obj1).forEach(function(key) {
        pushIntoObj3(key, obj1[key]);
    });

    Object.keys(obj2).forEach(function(key) {
        pushIntoObj3(key, obj2[key]);
    });

    function pushIntoObj3(key, val) {
        if (!obj3[key]) {
            obj3[key] = [];
        }
        obj3[key].push(val);
    }

    return obj3;
}

{
  "a": [ 1, 12 ],
  "b": [ 2 ],
  "c": [ 20 ]
}