需求：
1.可以简单地核对账号和密码；
2.给定一个本金，可以实现简单的收支计算；
3.可以查询收支明细。
代码模块：
package 基础语法;//家庭收入支出明细import java.util.Scanner;public class Demo5 {public static void main(String[] args) {flag1:while (true) {System.out.println("请输入账号");Scanner scanner = new Scanner(System.in);int Account = scanner.nextInt();if (Account != 1111) {System.out.println("账号错误,请重新输入");continue flag1;} else {System.out.println("请输入密码");int passward = scanner.nextInt();if (passward != 2222) {System.out.println("密码错误");continue flag1;} else {flag:while (true) {System.out.println("----------家庭收支记账软件----------");System.out.println("1.收支明细");System.out.println("2.登记支出");System.out.println("3.登记收入");System.out.println("4.查看余额");System.out.println("5.退出");System.out.println("请选择（1-5）：");int money = 10000;Scanner sc = new Scanner(System.in);String arr[][] = new String[1000][4];int count = 0;boolean flag2 = true;while (flag2) {int a = sc.nextInt();if (a == 2) {System.out.println("请输入支出金额");int out = sc.nextInt();System.out.println("请输入支出明细");String s2 = sc.next();arr[count][0] = "收入";money -= out;//总余额等于基础的加收入的arr[count][1] = String.valueOf(money);//直接把sumNum和num都转换成字符串类型arr[count][2] = String.valueOf(out);arr[count][3] = s2;System.out.println("---请继续执行---");count++;} else if (a == 3) {System.out.println("请输入收入金额");int in = sc.nextInt();System.out.println("请输入收入明细");String s1 = sc.next();arr[count][0] = "收入";money -= in;//总余额等于基础的加收入的arr[count][1] = String.valueOf(money);//直接把sumNum和num都转换成字符串类型arr[count][2] = String.valueOf(in);arr[count][3] = s1;System.out.println("---请继续执行---");count++;} else if (a == 1) {System.out.println("收支账户总金额收支金额说 明");for (int i = 0; i < arr.length; i++) {//循环打印 输入的数据if (arr[i][0] != null) {System.out.println(arr[i][0] + "" + arr[i][1] + " " + arr[i][2] + " " + arr[i][3]);}}System.out.println("---请继续执行---");} else if (a == 4) {System.out.println("余额为：" + money);} else if (a == 5) {System.out.println("-----重新登录软件请按1-----");System.out.println("-----退出本系统请按2-----");int b = sc.nextInt();if (b == 1) {break flag;} else {break flag1;}} else {System.out.println("指令错误，请重新操作");flag2 = false;}}}}}}}}
运行结果演示：
