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" );

          }

    }

}