编程题：jmu-Java-06异常-01-常见异常

import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int[] array = new int[5]; // 定义一个大小为5的数组
while (scanner.hasNext()) {
String input = scanner.next();
try {
switch (input) {
case "arr":
int index = scanner.nextInt();
System.out.println(array[index]); // 尝试访问数组的给定索引
break;
case "null":
Object obj = null;
System.out.println(obj.toString()); // 尝试调用一个null对象的方法
break;
case "cast":
Object str = "test";
Integer num = (Integer) str; // 尝试将String对象转为Integer对象
break;
case "num":
String value = scanner.next();
In