疑問 - 如何改成抽象類別

[leowang]

PHP 語法:

interface Data
{   
   public void showData();   
}
interface Test
{
   public void showScore();
   public double calcu();
}
class CStu implements Data,Test
{
   protected String id;    // 學號
   protected String name;  // 姓名 
   protected int mid;      // 期中考成績
   protected int finl;     // 期末考成績
   protected int common;   // 平時成績
       
   public CStu(String s1,String s2,int m,int f,int c)
   {
      id=s1;
      name=s2;
      mid=m;
      finl=f;   
      common=c;   
   }
   public void show()
   {
      showData();
      showScore();
   }
   public void showScore()
   {
      System.out.println("期中考成績:"+mid);
      System.out.println("期末考成績:"+finl);
      System.out.println("平時成績:"+common);
      System.out.println("學期成績:"+calcu());
   }
   public void showData()
   {
      System.out.println("學號:"+id);
      System.out.println("姓名:"+name);
   }
   public double calcu()
   {
      return (mid*0.3+finl*0.3+common*0.4);      
   }
}

public class hw11_11
{
   public static void main(String args[])
   {
      CStu stu=new CStu("940001","Fiona",90,92,85);
      stu.show();
   }
} 


請問上列程式碼如何改成抽象類別的形式

[snoopy]

雖然我不知道為什麼你要這要做
不過很好改

interface Data 
{    
   public void showData();    
} 
interface Test 
{ 
   public void showScore(); 
   public double calcu(); 
} 
abstract class CStu implements Data,Test 
{ 
   protected String id;    // 學號 
   protected String name;  // 姓名  
   protected int mid;      // 期中考成績 
   protected int finl;     // 期末考成績 
   protected int common;   // 平時成績 
        
   public CStu(String s1,String s2,int m,int f,int c) 
   { 
      id=s1; 
      name=s2; 
      mid=m; 
      finl=f;    
      common=c;    
   } 
   public void show() 
   { 
      showData(); 
      showScore(); 
   } 
   public void showScore() 
   { 
      System.out.println("期中考成績:"+mid); 
      System.out.println("期末考成績:"+finl); 
      System.out.println("平時成績:"+common); 
      System.out.println("學期成績:"+calcu()); 
   } 
   public void showData() 
   { 
      System.out.println("學號:"+id); 
      System.out.println("姓名:"+name); 
   } 
   public double calcu() 
   { 
      return (mid*0.3+finl*0.3+common*0.4);       
   } 
} 

class SubClass extends CStu{
	public SubClass(String s1,String s2,int m,int f,int c){
		super(s1,s2,m,f,c);
	}
}

public class App 
{ 
   public static void main(String args[]) 
   { 
      CStu stu=new SubClass("940001","Fiona",90,92,85); 
      stu.show(); 
   } 
}

[leowang]

沒有辦法把介面改成抽象類別嗎........

[snoopy]

可以啊
不過 java 是單一繼承制
所以你只能繼承其中一個類別

你想把兩個介面都改抽象類別
然後繼承這兩個類別就不行

[leowang]

作者: snoopy

可以啊
不過 java 是單一繼承制
所以你只能繼承其中一個類別

你想把兩個介面都改抽象類別
然後繼承這兩個類別就不行

那依大大所說 要如何來做修改呢

[snoopy]

interface Data {
	public void showData();
}

abstract class Test {
	abstract public void showScore();

	abstract public double calcu();
}

class CStu extends Test implements Data {
	protected String id; // 學號 

	protected String name; // 姓名  

	protected int mid; // 期中考成績 

	protected int finl; // 期末考成績 

	protected int common; // 平時成績 

	public CStu(String s1, String s2, int m, int f, int c) {
		id = s1;
		name = s2;
		mid = m;
		finl = f;
		common = c;
	}

	public void show() {
		showData();
		showScore();
	}

	public void showScore() {
		System.out.println("期中考成績:" + mid);
		System.out.println("期末考成績:" + finl);
		System.out.println("平時成績:" + common);
		System.out.println("學期成績:" + calcu());
	}

	public void showData() {
		System.out.println("學號:" + id);
		System.out.println("姓名:" + name);
	}

	public double calcu() {
		return (mid * 0.3 + finl * 0.3 + common * 0.4);
	}
}

public class App {
	public static void main(String args[]) {
		CStu stu = new CStu("940001", "Fiona", 90, 92, 85);
		stu.show();
	}
}

[leowang]

作者: snoopy

interface Data {
	public void showData();
}

abstract class Test {
	abstract public void showScore();

	abstract public double calcu();
}

class CStu extends Test implements Data {
	protected String id; // 學號 

	protected String name; // 姓名  

	protected int mid; // 期中考成績 

	protected int finl; // 期末考成績 

	protected int common; // 平時成績 

	public CStu(String s1, String s2, int m, int f, int c) {
		id = s1;
		name = s2;
		mid = m;
		finl = f;
		common = c;
	}

	public void show() {
		showData();
		showScore();
	}

	public void showScore() {
		System.out.println("期中考成績:" + mid);
		System.out.println("期末考成績:" + finl);
		System.out.println("平時成績:" + common);
		System.out.println("學期成績:" + calcu());
	}

	public void showData() {
		System.out.println("學號:" + id);
		System.out.println("姓名:" + name);
	}

	public double calcu() {
		return (mid * 0.3 + finl * 0.3 + common * 0.4);
	}
}

public class App {
	public static void main(String args[]) {
		CStu stu = new CStu("940001", "Fiona", 90, 92, 85);
		stu.show();
	}
}

非常感謝大大的解答......大概知道怎修改了