Java List接口的集合使用详解

import java.util.ArrayList;

public class dome2{
	public static void main(String[] args){
          ArrayList list=new ArrayList();
          list.add("nihoa"); //添加字符串
          list.add(12);   //添加数字
          list.add('a');   //添加字符
          list.add("hello");
          list.set(1,"java"); //将索引为1的换成字符串
          System.out.println("索引为2的值是："+list.get(2));
          System.out.println("删除索引为0的值是:"+list.remove(0));
          System.out.println("列表中还有"+list.size()+"个元素");
          System.out.println("判断列表是不是为空: "+list.isEmpty());
          for (Object object : list) {   //循序打印
			System.out.print(object+" ");
		}
          
   }
}

class Goods{
	private int id;    //编号
	private String name;   //名称
	private float price;   //价格
	public Goods() {
		
	}
	public Goods(int id, String name, float price) {
		super();
		this.id = id;
		this.name = name;
		this.price = price;
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public float getPrice() {
		return price;
	}
	public void setPrice(float price) {
		this.price = price;
	}
	@Override
	public String toString() {    //格式输出
		return "商品编号: "+id+", 名称: "+", 价格: "+",";
	}
	
}

import java.util.ArrayList;


public class dome2{
	public static void main(String[] args){
          ArrayList<Goods> list=new ArrayList<Goods>();
          list.add(new Goods(1,"保温杯",22.0f));
          list.add(new Goods(2,"洗发水",21.3f));
          list.add(new Goods(3,"笔记本",5.0f));
          Goods g=new Goods(5,"热水壶",59.0f);
          list.add(g);
          list.add(new Goods(4,"菜刀",31.4f));
          
          //1.遍历所有商品
          for(int i=0;i<list.size();i++) {
        	  System.out.println(list.get(i).toString());
          }
          //2.获取指定商品的信息
          System.out.println("查找编号为3,名称为热水壶,价格为59元的元素索引"+list.indexOf(g));
          System.out.println("热水壶的价格是 "+list.get(3).getPrice()+" 元");
          
          System.out.println("洗发水的编号是 "+list.get(1).getId());
          
          System.out.println("将菜刀的价格设为120元 ");
          list.get(list.size()-1).setPrice(120.0f);
          
        //3.遍历所有商品
          for(int i=0;i<list.size();i++) {
        	  System.out.println(list.get(i).toString());
          }
          
   }
}

public class dome2{
	public static void main(String[] args){
          ArrayList list=new ArrayList();
         list.add("hello ");
         list.add("world!,");
         list.add("hello ");
         list.add("java!");
         
         Iterator it=list.iterator();
         while(it.hasNext()) {  //判断是否还有下一个元素
        	 System.out.print(it.next());  //输出下一个元素
         }
   
   }
}

public class dome2{
	public static void main(String[] args){
         LinkedList list=new LinkedList();
         list.add("电风扇");
         list.add("吹风机");
         list.add("香皂");
         list.add("肥皂");
         list.add("洗发水");
         
         System.out.println("获取的第一个商品是: "+list.getFirst());
         System.out.println("获取的最后一个商品是: "+list.getLast());
         System.out.println("删除的第一个元素是: "+list.removeFirst());
         System.out.println("将索引为3的元素修改成: "+list.set(3,"牛角梳"));
         
         for(int i=0;i<list.size();i++) {
        	 System.out.print(list.get(i)+"\t");
         } 
   }
}