Java中泛型使用实例详解

ArrayList<Ls> ff=new ArrayList()<Ls>;Ls ls1=new Ls("薯片",5f);ff.add(ls1);Ls cls=ff.get(0);//这里不再需要强转  

import java.util.*;public class L4_6{  public static void main(String[] args)  {          //Hashtable ff=new Hashtable();              ArrayList ff=new ArrayList();       Ls ls1=new Ls("薯片",5f);       ff.add(ls1);     Ls cls=(Ls)ff.get(0);       Yl hyl=(Yl)ff.get(0);//这样显然是不对的     }}class Ls{  private String mingcheng;  private float jiage;   Ls(String mingcheng,float jiage)  {      this.mingcheng=mingcheng;      this.jiage=jiage;  }}class Yl{  private String mingcheng;  private float jiage;  private String yanse;   Yl(String mingcheng,float jiage,String yanse)  {      this.mingcheng=mingcheng;      this.jiage=jiage;      this.yanse=yanse;  }}