Firebase Push to Database with Array of Objects

Question

The firebase database push method adds an object to the database child with a unique key, e.g.,

postsRef.push({
  author: "gracehop",
  title: "Announcing COBOL, a New Programming Language"
});

puts something like the following in the database

"posts": {
    "-JRHTHaIs-jNPLXOQivY": {
      "author": "gracehop",
      "title": "Announcing COBOL, a New Programming Language"
    }

However, if I use the push method with an array of objects, e.g.

    postsRef.push({
        {
          author: "gracehop1",
          title: "Announcing COBOL, a New Programming Language"
        },
        {
          author: "gracehop2",
          title: "Announcing COBOL, a New Programming Language"
        }});

I get a single unique key with enumerated objects in the database, i.e.,

"posts": {
    "-JRHTHaIs-jNPLXOQivY": {
      "0": { 
         "author": "gracehop1",
         "title": "Announcing COBOL, a New Programming Language"
       },
      "1": {
         "author": "gracehop2",
         "title": "Announcing COBOL, a New Programming Language"
       }
     }}

Is there any way to push an array of objects in a single transaction such that i get a unique key for each object in the array, i.e., a result that looks something like

"posts": {
        "-JRHTHaIs-jNPLXOQivY": {
             "author": "gracehop1",
             "title": "Announcing COBOL, a New Programming Language"
         "-JRHTHaIs-jNPLXOQivZ": {
             "author": "gracehop2",
             "title": "Announcing COBOL, a New Programming Language"
           }
         }}

Answer 1

A little known fact is that you can call push() without any arguments and it will just generate a location/push id for you. With that and multi-location updates (see here and here), you can do:

var key1 = postsRef.push().key;
var key2 = postsRef.push().key;
var updates = {};
updates[key1] = {
      author: "gracehop1",
      title: "Announcing COBOL, a New Programming Language"
    };
updates[key2] = {
      author: "gracehop2",
      title: "Announcing COBOL, a New Programming Language"
    };
ref.update(updates);