自己写一个家庭收支账单(没写完但意思到了)

分手后的思念是犯贱 2022-04-13 06:23 151阅读 0赞

第一步先分析需求  
需要什么变量  
int balance = 10000;  
        String details = "收支 \\t账户金额 \\t收支金额 \\t说  明"+"\\n";  
        boolean loopFlag = true;  
先写框架用循环实现选择框  
打印  
然后从键盘输入选择项  
退出要有相应的机制保护

package com.xatu.edu;
    
    public class shouzhi {
    
    	public static void main(String[] args) {
    		// 声明余额变量，10000
    		// 声明记账本 初始化表头
    		// 声明布尔变量作为循环条件
    		// 再循环中
    		// 1打印主菜单
    		// 2获取用户的键盘输入
    
    		int balance = 10000;
    		String details = "收支 \t账户金额 \t收支金额 \t说  明"+"\n";
    		boolean loopFlag = true;
    		while (loopFlag) {
    			System.out.println("-----------------家庭收支记账软件-----------------");
    			System.out.println("   1 收支明细   ");
    			System.out.println("    2 登记收入    ");
    			System.out.println("3 登记支出");
    			System.out.println("4 退    出");
    			System.out.println(" 请选择(1-4)：");
    			char userInput = Utility.readMenuSelection();
    			switch (userInput) {
    			case '1':
    				System.out.println(details);
    				break;
    			case '2':
    				System.out.println("输入金额");
    				int money = Utility.readNumber();
    				System.out.println("输入金额说明");
    				String info = Utility.readString();
    				balance=balance+money;
    				String 	str ="收入\t"+balance+"\t"+money+"\t"+info+"\n";
    				details +=str;
    				break;
    			case '3':
    
    				break;
    			case '4':
    				System.out.println("退出出马,");
    				char confirm = Utility.readConfirmSelection();
    				if(confirm=='Y') {
    				loopFlag = false;}
    				break;
    
    			default:
    				break;
    			}
    
    		}
    
    	}
    
    }

package com.xatu.edu;
    
    import java.util.*;
    
    public class Utility {
        private static Scanner scanner = new Scanner(System.in);
        
    	public static char readMenuSelection() {
            char c;
            for (; ; ) {
                String str = readKeyBoard(1);
                c = str.charAt(0);
                if (c != '1' && c != '2' && c != '3' && c != '4') {
                    System.out.print("选择错误，请重新输入：");
                } else break;
            }
            return c;
        }
    
        public static int readNumber() {
            int n;
            for (; ; ) {
                String str = readKeyBoard(4);
                try {
                    n = Integer.parseInt(str);
                    break;
                } catch (NumberFormatException e) {
                    System.out.print("数字输入错误，请重新输入：");
                }
            }
            return n;
        }
    
        public static String readString() {
            String str = readKeyBoard(8);
            return str;
        }
    
        public static char readConfirmSelection() {
            char c;
            for (; ; ) {
                String str = readKeyBoard(1).toUpperCase();
                c = str.charAt(0);
                if (c == 'Y' || c == 'N') {
                    break;
                } else {
                    System.out.print("选择错误，请重新输入：");
                }
            }
            return c;
        }
    
        private static String readKeyBoard(int limit) {
            String line = "";
    
            while (scanner.hasNext()) {
                line = scanner.nextLine();
                if (line.length() < 1 || line.length() > limit) {
                    System.out.print("输入长度（不大于" + limit + "）错误，请重新输入：");
                    continue;
                }
                break;
            }
    
            return line;
        }
    }