public class LibraryMenu {
static Scanner input = new Scanner(System.in);
static Holding[]holding = new Holding[15];
static Member[]member = new Member[15];
static int hold = 0;
private static Scanner scanner;
public static void main(String[] args){
int options;
do{
scanner = new Scanner(System.in);
System.out.println();
System.out.println("Library Management System");
System.out.println("1. Add Holding");
System.out.println("2. Print All Holding");
options = scanner.nextInt();
switch(options){
case 1:
addHolding();
break;
case 2:
print();
break;
default:
System.out.println("Please");
}
}while(options != 3);
System.out.println("I'm out");
}
public static void addHolding(){
int options1;
do{
System.out.println();
System.out.println("1. Book");
System.out.println("2. Video");
System.out.println("3. Return");
options1 = input.nextInt();
switch(options1){
case 1:
addBook();
break;
case 2:
addVideo();
break;
default:
System.out.println("Please enter the following options");
}
}while(options1 != 3);
}
public static void addBook(){
System.out.println("Title: " + "\t");
String title = input.next();
System.out.println("ID: " + "\t");
String holdingId = input.next();
Book tempbook = new Book(title, holdingId);
holding[hold] = tempbook;
++hold;
}
public static void addVideo(){
System.out.println("Title: ");
String title = input.next();
System.out.println("ID: ");
String holdingId = input.next();
System.out.println("Loan Fee: ");
int loanFee = input.nextInt();
Video tempvideo = new Video(holdingId, title, loanFee);
holding[hold] = tempvideo;
++hold;
}
public static void print(){
for(int i = 0; i < holding.length; i++){
System.out.println(holding[i]);
}
}
}
当我使用print（）方法时，没有任何显示。想知道代码有什么问题，以及为什么不打印出来。使用用户输入来添加书籍和视频等。试图在互联网上查找此问题，但似乎无法找到它。