Java ArrayList 不为人知的陷阱，及add(int index, E element)和set(int index, E element)两个方法的说明 public class ArrayListTest { public static void main(String[] args) { List list = new ArrayList(2); System.out.println("lis
public class ArrayListTest {
public static void main(String[] args) {
List
list = new ArrayList<>(2);
System.out.println("list大小为：" + list.size());
list.add("12");
System.out.println("list大小为：" + list.size());
list.set(1,"sss");
list.add(1,"放在下标为1的位置");
list.add("22");
System.out.println("list大小为：" + list.size());
System.out.println(list.toString());
list.add(1,"放在下标为1的位置");
System.out.println("list大小为：" + list.size());
System.out.println(list.toString());
}
}