java控制台程序：简单管理系统

import java.util.Scanner;

public class ZhouEr {

    public static void main(String[] args) {
        
        int [] arr1 = new int[5];
        String arr2[] = new String[5];
        double [] arr3 = new double[5];
        
        Scanner sca = new Scanner(System.in);
        
        int i ;
        int count = 0;
        while(true){
            System.out.println("=图书管理系统1.0=");
            System.out.println("1.添加");
            System.out.println("2.修改");
            System.out.println("3.删除");
            System.out.println("4.查询");
            System.out.println("5.退出");
            int book = sca.nextInt();
            if(book == 1){
                System.out.println("添加图书");
                System.out.print("--输入图书编号");

                arr1[count] = sca.nextInt();

                System.out.print("--输入图书名");
                arr2[count] = sca.next();
                System.out.print("--输入图书价格");
                arr3[count] = sca.nextDouble();
                System.out.println("成功添加");
                count ++;
                for(int j = 0;j <count;j++){
                    if(arr1[j]==0){
                        break;
                    }
                    System.out.println("已经添加的是："+arr1[j]+arr2[j]+arr3[j]);
                }
            }else if(book == 2){
                System.out.println("修改图书");
                System.out.print("选择要修改的图书编号：");
                int upId = sca.nextInt();
                for(int ii = 0; ii < arr1.length; ii ++) {
                    if(upId == arr1[ii]) {
                    System.out.print("--输入图书名");
                    arr2[ii] = sca.next();
                    System.out.print("--输入图书价格");
                    arr3[ii] = sca.nextDouble();
                    System.out.println("成功修改");
                    }
                }
                for(int j = 0;j <5;j++){
                    if(arr1[j]==0){
                        break;
                    }
                    System.out.println("修改后的书库是："+arr1[j]+arr2[j]+arr3[j]);
                }
                
            }else if(book == 3){
                System.out.println("删除图书");
                System.out.print("选择要删除的图书编号：");
                int upId = sca.nextInt();
                for(int k = 0;k < arr1.length;k ++) {
                    if(upId == arr1[k]) {
                        for(int g = k;g < arr1.length-1;g ++) {
                            arr1[g] = arr1[g + 1];
                        }
                    }
                }
//              arr1[upId-1] = 0;
//              arr2[upId-1] = null;
//              arr3[upId-1] = 0.0;
                
                for(int j = 0;j <5;j++){
                    if(arr1[j]==0){
                        break;
                    }
                    System.out.println("删除后的书库是："+arr1[j]+arr2[j]+arr3[j]);
                }
            }else if(book == 5){
                System.out.println("退出系统");
                return;
            }
        }
    }
}