Question

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();
   }
}

Answer 1

Integer类没有getValue（）方法。有intValue()方法。但对于算术运算，您甚至不必调用它 - Java将执行autoboxing：

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

Answer 2

Class Integer没有方法 getValue

Answer 3

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

或

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

或

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

找不到符号-method getvalue（）;也许你的意思是：intValue

3 个答案: