JavaSE 第四十讲 ArrayList 源代码 11.2-11.3

package com.shengsiyuan;

import java.util.ArrayList;

public class ArrayListTest1
{
    public static void main(String[] args)
    {
        ArrayList arrayList = new ArrayList();
        
        arrayList.add("hello");
        arrayList.add("world");
        arrayList.add("welcome");
        
        String s1 = (String)arrayList.get(0);
        String s2 = (String)arrayList.get(1);
        String s3 = (String)arrayList.get(2);
        
        System.out.println(s1);
        System.out.println(s2);
        System.out.println(s3);
        
        //arrayList.clear();
        //System.out.println(arrayList.isEmpty());
        
        arrayList.remove(0);
        
        System.out.println("_______________");
        
        for(int i = 0; i < arrayList.size(); i++)
        {
            System.out.println(arrayList.get(i));
        }
        
        System.out.println("----------------");
        
        arrayList.add("aaa");
        arrayList.add("bbb");
        
        System.out.println(arrayList.indexOf("aaa"));
        
    }
    
}

package com.shengsiyuan;

import java.util.ArrayList;

public class ArrayListTest2
{
    public static void main(String[] args)
    {
        ArrayList list = new ArrayList();
        
        list.add("hello");
        list.add(new Integer(2));
        
        String str = (String)list.get(0);
        Integer in = (Integer)list.get(1);
        
        System.out.println(str);
        System.out.println(in.intValue());  
    }
}

package com.shengsiyuan;

import java.util.ArrayList;

public class ArrayListTest3
{
    public static void main(String[] args)
    {
        ArrayList list = new ArrayList();
        
        list.add(new Integer(3));
        list.add(new Integer(4));
        list.add(new Integer(5));
        list.add(new Integer(6));
        
        int sum = 0;
        
        for(int i = 0; i < list.size(); i++)
        {
            int value = ((Integer)list.get(i)).intValue();
            
            sum += value;
        }
        
        System.out.println(sum);
        
    }
}

package com.shengsiyuan;

import java.util.ArrayList;

public class ArrayListTest4
{
    public static void main(String[] args)
    {
        ArrayList list = new ArrayList();
        
        list.add(new Integer(1));
        list.add(new Integer(2));
        list.add(new Integer(3));
        list.add(new Integer(4));
        list.add(new Integer(5));
        list.add(new Integer(6));
        
        Object[] in = list.toArray();
        
        for(int i = 0; i < in.length; i++)
        {
            System.out.println(((Integer)in[i]).intValue());
        }
    }
}

package com.shengsiyuan;

import java.util.ArrayList;

/**
 * 
 * @author Administrator
 *
 */

public class ArrayListTest5
{
    public static void main(String[] args)
    {
        ArrayList list = new ArrayList();
        
        list.add(new Point(2, 3));
        list.add(new Point(2, 2));
        list.add(new Point(4, 4));
        
        for(int i = 0; i < list.size(); i++)
        {
            System.out.println(list.get(i));
        }
        
        System.out.println(list);
    }
}

class Point
{
    int x;
    int y;
    
    Point(int x, int y)
    {
        this.x = x;
        this.y = y;
    }
    
    public String toString()
    {
        return "x=" + this.x + ", y="+ this.y;
    }
}