小白日记之List篇，java学习之路开启-原创手记-慕课网

Collection是所有集合的接口
都是java.util.*包下的
List是接口（ArrayList，LinkedList)是它的重要实现类
List和数组相似，有序并且长度可以变化

泛型List<PhoneType> 变量list全部存储的都是PhoneType的对象
可以添加泛型子类型的对象实例
package Y1_28;
import java.util.*;
public class ListTest {
public static void main(String[] args) {
ListTest lt = new ListTest();

    PhoneType pt1 = new PhoneType("OPPO",6373392);
    PhoneType pt2 = new PhoneType("三星",6060950);
    PhoneType pt3 = new PhoneType("华为",5904723);
    PhoneType pt4 = new PhoneType("苹果",5826622);

    PhoneType[] arrPt = {pt3,pt4};
    List<PhoneType> list = new ArrayList<PhoneType>();
    //add()添加
    list.add(new PhoneType("vivo",8330510));
    //list.add(new Integer(1));  泛型起了作用，如果没加则不会报错
    //可以选择位置存储，不能越界
    list.add(1, pt1);
    //查！！！！！！！asList
    list.addAll(Arrays.asList(arrPt));
    //显示手机信息
    lt.showPhone(list);
    System.out.println("-----------------------");

    //修改list中存储的元素get();
    System.out.println("将苹果修改为英文");
    list.set(3, new PhoneType("Apple",5826622));
    System.out.println("修改过后的手机型号:"+list.get(3).getLogo());
    System.out.println("修改成功！");

    //删除一个元素remove();
    System.out.println("去掉三星手机");
    list.remove(pt2); //list.remove(2);同样效果
    System.out.println("-----------------------");
    lt.showPhone(list);
    System.out.println("成功去除");
}

public void showPhone(List list){
    //用Iterate迭代遍历,此时也应该用泛型
            Iterator<PhoneType> it = list.iterator();
            while(it.hasNext())
            {
                PhoneType temp = it.next();
                System.out.println("手机产销排行："+temp.getLogo()+" 热度为"+temp.getPopular());
            }

}

}
class PhoneType{
private String logo;
private long popular;
PhoneType(String logo,long popular)
{
this.logo = logo;
this.popular = popular;
}
public long getPopular() {
return popular;
}
public void setPopular(long popular) {
this.popular = popular;
}
public String getLogo() {
return logo;
}
}