ArrayList

package ArrayListT;

import java.util.ArrayList;

public class ArrayListTest1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        ArrayList<String> arrayList = new ArrayList<String>();
        //ArrayList arrayList = new ArrayList();
        //共有的方法
        arrayList.add("1");
        arrayList.add("2");
        arrayList.add("4");
        arrayList.add("5");
        arrayList.add(2, "3");
        System.out.println(arrayList);//1,2,3,4,5
        int lenght = arrayList.size();//5
        System.out.println(lenght);//5
        String two = arrayList.get(2);//强制转换  3
        System.out.println(two); //3
        System.out.println(arrayList.contains("6"));//false
        arrayList.remove("5");//1,2,3,4
        System.out.println(arrayList.size());//4
        arrayList.remove(0);//2,3,4
        System.out.println(arrayList.contains("1"));//false
        System.out.println(arrayList.indexOf("2"));//0
        System.out.println(arrayList.lastIndexOf("4"));//2
        arrayList.set(0, "0");//0,3,4
        System.out.println(arrayList.contains("2"));//false
        System.out.println(arrayList.indexOf("0"));//0
        
        //存对象数据
        ArrayList<News> arrayList2 = new ArrayList<News>();
        News news0 = new News("1", "12");
        News news1 = new News("2", "23");
        News news2 = new News("3", "34");
        News news3 = new News("4", "45");
        arrayList2.add(news0);
        arrayList2.add(news1);
        arrayList2.add(news2);
        arrayList2.add(news3);
    }
    }

}