2020.8.27
阿新 • • 發佈:2020-12-17
學習內容
1、定義一個基類BaseClass,從它派生出類DerivedClass。BaseClass有成員函式fn1(),fn2(),DerivedClass也有成員函式fn1(),fn2()。在主函式中宣告一個DerivedClass的物件,分別用DerivedClass的物件以及BaseClass的物件來呼叫fn1(),fn2(),觀察執行結果。
1 //BaseClass類: 2 public class BaseClass { 3 public void fn1() { 4 System.out.println("BaseClass類fn1函式"); 5 } 6 public void fn2() { 7 System.out.println("BaseClass類fn2函式"); 8 } 9 } 10 //DerivedClass類: 11 public class DerivedClass { 12 public void fn1() { 13 System.out.println("DerivedClass類fn1函式"); 14 } 15 public void fn2() { 16 System.out.println("DerivedClass類fn2函式"); 17 } 18 19 public static void main(String[] args) { 20 DerivedClass a=new DerivedClass(); 21 BaseClass b=new BaseClass(); 22 a.fn1(); 23 a.fn2(); 24 b.fn1(); 25 b.fn2(); 26 } 27 }
2、定義一個Document類,有資料成員name,從Document派生Book類,增加資料成員pageCount。
1 //Document類: 2 public class Document { 3 protected String name; 4 Document(String n){ 5 name=n; 6 } 7 } 8 //Book類: 9 public class Book extends Document { 10 private int pageCount; 11 Book(String n,int p){ 12 super(n); 13 pageCount=p; 14 } 15 public void show() { 16 System.out.println("檔名:"+name+"\n頁數:"+pageCount); 17 } 18 19 public static void main(String[] args) { 20 Book a=new Book("書",100); 21 a.show(); 22 } 23 }