Question

I do have a collection and i need to go through the collection, and alter the data if necessary and push to an array.

 {
"Beatles": [
      {"name":"Album 1", "rate":"70"},
      {"name":"Album 2", "rate":"75"},
      {"name":"Album 3", "rate":"82"},
      {"name":"Album 4", "rate":"60"}
], 
"Purple" :[
      {"name":"Album 1", "rate":"30"},
      {"name":"Album 2", "rate":"90"},
      {"name":"Album 3", "rate":"23"},
      {"name":"Album 4", "rate":"14"}
]
}

// I want to go through the collection and save only the rates of Beatles album to an array, so it will look like this
myBeattlesarray = [70,75,82,60];

what is the best way to achieve this. thanks

Answer 1

You can use the Underscore pluck to get one field from the collection:

_.pluck(collection.Beatles, "rate");

---

var model = new Backbone.Model(
{
"Beatles": [
  {"name":"Album 1", "rate":"70"},
  {"name":"Album 2", "rate":"75"},
  {"name":"Album 3", "rate":"82"},
  {"name":"Album 4", "rate":"60"}
], 
"Purple" :[
  {"name":"Album 1", "rate":"30"},
  {"name":"Album 2", "rate":"90"},
  {"name":"Album 3", "rate":"23"},
  {"name":"Album 4", "rate":"14"}
]
}
);

var beatles = model.get("Beatles");
var rates = _.pluck(beatles, "rate");

console.log(rates);

Fiddle: http://jsfiddle.net/k5AVE/