日期:2014-05-20  浏览次数:20748 次

关于SET的小问题
import   java.util.*;
class   TextSet
{
public   static   void   main(String   []   args)
{
  HashSet <Student>   h=new   HashSet <Student> ();
  h.add(new   Student(2, "aaa "));
  h.add(new   Student(2, "aaa "));
  h.add(new   Student(1, "LHX "));
 
  Iterator   i=h.iterator();
  while(i.hasNext())
  System.out.println(i.next());
 
}
}
class   Student
{
int   num;
String   name;
Student(int   num,String   name)
{
this.num=num;
this.name=name;
}
public   String   toString()
{
return   num+ ": "+name;
}
public   int   hashcode()
{
              return   num*(name.hashCode());
}
public   boolean   equals(Object   o)
{
Student   s=(Student)o;
return   (num==s.num)&&(name.equals(s.name));
}
}

帮忙看看哪错了.怎么还有重复的元素呢!

------解决方案--------------------
public int hashCode() {
return num * (name.hashCode());
}

hashCode,大小写错了!
------解决方案--------------------
又是一个大小写的问题:

public int hashCode() //在你的程序里hsahCode是小写,就这个原因,以后细心点就行了!
{
return num*(name.hashCode());
}