Array和List之间的相互转化

Array转化为List

//array转化为list
 		//需要转化的arr1
        String [] arr1 = new String[]{"test1","test2"};
        //方法1，arrayLiast是转后的List
        List list1 = Arrays.asList(arr1);
        ArrayList<String> arrayList = new ArrayList<>(list1);
        arrayList.add("test3");
        System.out.println();
        for(String str: arrayList){
            System.out.println(str);
        }
        //方法二：arrayLiast1是转后的List
        ArrayList<String> arrayList1 = new ArrayList<>(arr1.length);
        Collections.addAll(arrayList1,arr1);
        System.out.println();
        for(String str: arrayList1){
            System.out.println(str);
        }
           

List转为Array

//List 转Array，必须使用集合的 toArray(T[] array)
        List<String> list = new ArrayList<>();
        list.add("wahaha");
        list.add("shuangwaiwia");
        //使用泛型，无需显示类型转化
        String[] arr = list.toArray(new String[list.size()]);
        System.out.println(Arrays.toString(arr));