61B-8: Inheritance, Implements

2024-07-14 193 words One minute

Contents

but hard to maintain!

Hypernyms, Hyponyms, and Interface Inheritance

interface

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public interface List61B<Item> {
   public void addFirst(Item x);
   public void addLast(Item y);
   public Item getFirst();
   public Item getLast();
   public Item removeLast();
   public Item get(int i);
   public void insert(Item x, int position);
   public int  size();
}

Overriding vs. Overloading

override注意加上@Override!!!

Interface Inheritance

基类存放指针问题 Answer: If X is a superclass of Y, then memory boxes for X may contain Y.

An AList is-a List.
Therefore List variables can hold ALList addresses.

Implementation Inheritance: Default Methods

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public interface List61B<Item> {
   public void addFirst(Item x);
   public void addLast(Item y);
   public Item getFirst();
   public Item getLast();
   public Item removeLast();
   public Item get(int i);
   public void insert(Item x, int position);
   public int size();  
   default public void print() {
      for (int i = 0; i < size(); i += 1) {
         System.out.print(get(i) + " ");
      }
      System.out.println();
   }
}

Static and Dynamic Type, Dynamic Method Selection ⚠️ ⚠️ ⚠️

More Dynamic Method Selection, Overloading vs. Overriding ⚠️ ⚠️ ⚠️

紧紧盯住细节！

Interface vs. Implementation Inheritance