collection.add

addcollection.add(models, [options])
Add a model (or an array of models) to the collection, firing an "add" event for each model, and an "update" event afterwards. If a model property is defined, you may also pass raw attributes objects, and have them be vivified as instances of the model. Returns the added (or preexisting, if duplicate) models. Pass {at: index} to splice the model into the collection at the specified index. If you're adding models to the collection that are already in the collection, they'll be ignored, unless you pass {merge: true}, in which case their attributes will be merged into the corresponding models, firing any appropriate "change" events.

var ships = new Backbone.Collection;

ships.on("add", function(ship) {
  alert("Ahoy " + ship.get("name") + "!");
});

ships.add([
  {name: "Flying Dutchman"},
  {name: "Black Pearl"}
]);

Note that adding the same model (a model with the same id) to a collection more than once
is a no-op.