class AnimalClass: NSObject {

    var cats = [catClass]()
    ..... 
}

和

class catClass: NSObject {

var name : String = ""

init(data : NSDictionary)
{
    if let add = data["name"] as? String
    {
        self.name = add
    }

在这里,我试图在ViewController.swift中初始化它

var animals = [AnimalClass]()
for(var i = 0; i < data_array.count; i++)
{
    if let add = data_array[i] as? NSDictionary
    {
      self.animals.append(AnimalClass(data: add)) // this works
      self.animals.cats.append(AnimalClass(data: add)) // this doesn't work
    }
}

我的问题是这行self.animals.cats.append(AnimalClass(data：add))如何追加到AnimalClass中的对象.