ArrayList练习

import java.util.*;

public class test11 {
    public static void main(String[] args) {
        List<Integer> arr =new ArrayList<>(5);
        System.out.println("1: "+arr);
        arr.add(0,12);
        arr.add(1,45);
        arr.add(2,63);
        arr.add(3,47);
        arr.add(4,96);
        //arr.add(3,24); 如果一开始直接add索引3，会出错
        //Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 3, Size: 2
        //超出范围
        List sub=arr.subList(1,3);
        System.out.println("2: "+sub);
        arr.addAll(3,sub);
        System.out.println("3: "+arr);    //从索引3后面加入另外整个List
        System.out.println("4: "+arr.contains(45)+" "+arr.contains(58));
        arr.add(arr.size(),11);
        System.out.println("5: "+arr);
        System.out.println("6: "+arr.indexOf(47));
        arr.remove(2);
        System.out.println("7: "+arr);
        List sub2= arr.subList(1,5);
        System.out.println("8: "+arr.containsAll(sub2)+" "+sub2.containsAll(arr));
        //System.out.println("8: "+arr.containsAll(sub));
        Collections.sort(arr);
        System.out.println("9: "+arr);
        ArrayList copy=new ArrayList<>(arr);
        System.out.println("10: "+copy);
        Collections.shuffle(arr);
        System.out.println("11: "+arr+" "+copy);
        int[] a2=new int[]{11,22,33,45,96};
        List arr2=Arrays.asList(11,22,33,45,96);
        //List arr2=Arrays.asList(a2);     //这里是把a2这个数组当成一个int[]类型整个传入  转化成一个只有一个元素的List
        System.out.println("12: "+arr2);
        arr.retainAll(arr2);
        System.out.println("13: "+arr);
        System.out.println("14: "+arr.isEmpty());
        arr.removeAll(arr2);
        System.out.println("15: "+arr+" "+arr.isEmpty());
    }
}