2011-01-26 62 views
0
import java.util.ArrayList; 
public class Averager { 

    private ArrayList list; 

    public Averager() { 
     list = new ArrayList(); 
    } 

    public void addGrades(int test, int quiz) { 
     list.add(new Integer(test)); 
     list.add(new Integer(test)); 
     list.add(new Integer(quiz)); 
    } 

    public double getAverage() { 
     int sum = 0; 
     for(int i = 0; i < list.size(); i++) { 
     sum += ((Integer)list.get(i)).getValue(); 
     } 
     return sum/list.size(); 
    } 
} 

回答

1

Integer类没有办法的getValue

3

Integer类不具备的getValue()方法。有intValue()方法。但是,对于算术运算,你甚至不必把它叫做 - Java将做autoboxing

sum += (Integer)list.get(i); 
+0

你甚至不给为你调用intValue,java auto-unboxes ints。它也会自动包装它们,所以不需要新的Integer。 – KitsuneYMG 2011-01-26 04:49:03

0
sum += ((Integer)list.get(i)).intValue(); 

sum += ((Integer)list.get(i)); 

sum += (Integer.parseInt((list.get(i)).toString())); 
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