mongodb push / pushall / pop

gistfile1.js

var document = { name: "jakub", surname: "oboza", games: []};
db.people.save(document);
var person = db.people.findOne({name: "jakub"});
person
{
	"_id" : ObjectId("4f65da9d8199c991088c9ca4"),
	"name" : "jakub",
	"surname" : "oboza",
	"games" : [ ]
}
db.people.update({_id: person._id}, { $pushAll: {games: ["Skyrim", "Fallout New Vegas"]} });
var person = db.people.findOne({name: "jakub"});
person
{
	"_id" : ObjectId("4f65da9d8199c991088c9ca4"),
	"games" : [
		"Skyrim",
		"Fallout New Vegas"
	],
	"name" : "jakub",
	"surname" : "oboza"
}
db.people.update({_id: person._id}, { $push: {games: "World of Warcraft" } });
db.people.findOne({name: "jakub"});
{
	"_id" : ObjectId("4f65da9d8199c991088c9ca4"),
	"games" : [
		"Skyrim",
		"Fallout New Vegas",
		"World of Warcraft"
	],
	"name" : "jakub",
	"surname" : "oboza"
}
var question = db.people.update({_id: person._id}, { $pop: { games: 1} });