Question

Lets say I have the following code:

public class Collection implements CollectionInterface{

 ElementInterface[] elementArray = new ElementInterface[100];
 int amountOfElements = 0;

 public Collection()
 {

 }

 public Collection(CollectionInterface collection)
 {
  CollectionInterface tempCollection = new Collection();
  while(!collection.isEmpty())
  {
   ElementInterface element = collection.Remove().clone();
   tempCollection.Add(element.clone2());
   elementArray[amountOfElements++] = element;
  }
  collection = tempCollection;

 }

 public void Add(ElementInterface element){
     elementArray[amountOfElements++] = element;
 }

 public ElementInterface Remove(){
  ElementInterface element = elementArray[amountOfElements].clone2();
  elementArray[amountOfElements] = null;
  amountOfElements--;
  return element;
 }

 public boolean isEmpty(){
  return amountOfElements == 0;
 }

 public CollectionInterface clone()
 {
  return new Collection(this);
 }
}

不管怎样,这似乎有点奇怪,而是有的。但是,如果我使用以下法典:

CollectionInterface collection = new Collection();
collection.Add(new Element("Foo"));
collection.Add(new Element("Bar"));
CollectionInterface collection2 = collection.clone();

第一种斜线更含有任何内容。如何做到这一点?

Answer 1

你不能改变投入参数的提法,因为你在第二位建筑商中尝试过。

collection = tempCollection.

a) is this a syntax error, b) collection is a local variable; assigning to it will change nothing on the outside of the constructor.

Answer 2

It makes perfect sense. In the constructor, which is called by clone() with the original collection as an argument, you use:

ElementInterface element = collection.Remove().clone();

因此,在你创建新收藏品时,请从原始收藏品中删除<>m>的内容。你们不想这样做......

鉴于你看上了<条码>,只见<>条码><>>>, 仅限<>>,<条码>和<条码>,>Remove <条/条码>方法(应为<条码>附加/条码>和<条码>> 移除,以便处理各种要素——不得以非破坏性方式获取收集。收集类型见very>/em> odd。难道你首先要这样做,而不是使用内在收集?

EDIT:Ah——我刚才有想法。 Within, 您可以查阅你重建的藏书的内部......这样,你就可以以破坏性的方式复制<> from。请通过打电话<代码>删除(现为您)重新收集资料,但当你建立你的阵列时,你可以使用:

for (int i = 0; i < amountOfElements; i++)
{
    collection.Add(elementArray[i].clone2());
}

......这将使精英们再次回头。页: 1 ......

Answer 3

你们只能实施以下克隆方法:

public Object Clone() {
    Collection rv = new Collection();

    for (ElementInterface element : elementArray) {
        rv.Add(element.clone());
    }

    return rv;
}

如果有必要,你可以很容易地在建筑商中执行。

友情链接