Mongojs - how to push to array?

Question

I have the following code:

db.users.save({
    username: "admin",
    array: [{
            foo1: "foo1",
            foo2: "foo2"
        }, {
            bar1: "bar1",
            bar2: "bar2"
        }, {
            cell1: "cell1",
            cell2: "cell2"
        }
    ]
});

Now I want to update the array. I mean to push something into the array:

db.users.update({
    username: admin
}, {
    $set: {
        array: {
            push1: "push1",
            push2: "push2"
        }
    },


    function (err, updated) {

The update function doesn't push. So how can I push to the array, so the result will be:

[
  { foo1:"foo1", foo2:"foo2" },
  { bar1:"bar1", bar2:"bar2" },
  { cell1:"cell1", cell2:"cell2" },
  { push1:"push1", push2:"push2" }
]

Answer 1

The $set operator will, of course, change the whole data of the array property.

If you want to just push, use $push (which pushes one item at once) or $pushAll (which pushes all items of an array).
If you want to push without repeating an item, use $addToSet.

Note: If you're on MongoDB 2.4 (the latest version), use $push with the new $each modifier. This deprecates usage of $pushAll (this applies to $addToSet, too)

Docs:

• $push
• $pushAll
• $addToSet