集合

List接口的实现类

• ArrayList实现了长度可变的数组，在内存中分配连续的空间。遍历元素和随机访问元素的效率比较高

• LinkedList采用链表存储方式。插入、删除元素时效率比较高

  
  

手动输入狗狗

package com.company;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;

/**
 * Created by ttc on 2018/1/8.
 */
public class ListDemo {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
//    String[] arrays = new String[100000000];
        List<String> listDogs = new ArrayList<>();//创建List集合对象

        while (true)
        {
            System.out.println("请输入一条狗的名字，no退出");
            String dogName = scanner.next();
            listDogs.add(dogName);//向List中添加元素

            if(dogName.equals("no"))
            {
                break;
            }
        }

        //遍历数组
        //listDogs.size()获得集合当前元素的个数
        for(int i = 0; i < listDogs.size(); i++)
        {
            System.out.println(listDogs.get(i));//listDogs.get(i)获得集合中第i个元素的值
        }

        System.out.println("退出了");
    }

}

手动输入删除喵星人

        Scanner scanner=new Scanner(System.in);
        List<String> listCats=new ArrayList<String>();
        while (true)
        {
            System.out.println("请输入一个喵星人的名字");
            String catName=scanner.next();
            if (catName.equals("no"))
            {
                break;
            }
            if (!listCats.contains(catName))
            {
                listCats.add(catName);
            }
        }
        System.out.println("需要删除第几条喵星人");
        int delete=scanner.nextInt();
        listCats.remove(delete);
        System.out.println("需要删除哪只喵星人");
        String delete1=scanner.next();
        listCats.remove(delete1);
        for (int i=0;i<listCats.size();i++)
        {
            System.out.println(listCats.get(i));
        }
        System.out.println("退出");

调用类的方法

 Scanner scanner=new Scanner(System.in);
        List<Cat> catList=new ArrayList<Cat>();
        while (true)
        {
            System.out.println("请输入喵星人的名字");
            String catName=scanner.next();
            if (catList.equals("no"))
            {
                break;
            }
            Cat cat=new Cat();
            cat.setName(catName);
            catList.add(cat);
            for (int i=0;i<catList.size();i++)
            {
                Cat cat1=catList.get(i);
                System.out.println(cat1.getName());
            }
            System.out.println("退出");
        }

类的编写
```java
package com.company;

/**
 * Created by ttc on 18-1-8.
 */
public class Cat {
    private String  name;
    private  int age;

    public String getName()
    {
        return name;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public int getAge()
    {
        return age;
    }

    public void setAge(int age)
    {
        this.age = age;
    }
}