有人可以看看我的 atm 项目代码吗？答案

【问题标题】：Can someone please look my code for atm project?有人可以看看我的 atm 项目代码吗？
【发布时间】：2021-10-13 13:08:37
【问题描述】：

目前，我正在从事一个 ATM 项目。我能够让它工作。但是，如果用户在 switch 语句中输入小写字母而不是大写字母，我不确定该怎么办。另外，我是否应该使用 while 循环，以便用户能够重复这些步骤。最后，我坚持如何让用户随时退出程序。例如，完成选择后退出。

public static void main(String[] args) {
    
    double checkingAccount = 5000;
    double savingAccount = 2000;
    
    Scanner cin = new Scanner(System.in);
    
    //Welcoming the user! 
    
    System.out.println("=======================");
    System.out.println("Welcome to SoundBank!");
    System.out.println("=======================");
    
    // Selections for the user
    System.out.println("Please choose: \nA - Checking Account \nB - Savings Account");
    String choice1 = cin.nextLine();
     
    System.out.println("Please choose of the following: \nD - Deposit \nW - Withdrawal \nC - Check Balance \nE - Exit");
    String choice2 = cin.nextLine();
    
    // It's time for loops
    
    
    
    switch (choice2) {
        case "D": 
            
            // Checking Account
            if (choice1.equalsIgnoreCase("A")) {
                
                System.out.println("How much you do you want to deposit?");
                double amount = cin.nextDouble();
                double total1 = checkingAccount + amount;
                System.out.println("You deposited " + amount);
                System.out.println("You currently have: " + total1);
                
            } else
            
            // Saving Account 
            if (choice1.equalsIgnoreCase("B")) {
                
                System.out.println("How much you do you want to deposit?");
                double amount2 = cin.nextDouble();
                double total2 = savingAccount + amount2;
                System.out.println("You deposited " + amount2);
                System.out.println("You currently have: " + total2);
                
            }  
            
            break;

        case "W":
            
            // Checking Account 
            if (choice1.equalsIgnoreCase("A")) {
                System.out.println("How much do you want to withdraw?");
                double amount3 = cin.nextDouble();
                double total3 = checkingAccount - amount3;
                System.out.println("You withdrew " + amount3);
                System.out.println("You currently have: " + total3);
            } else 
            // Saving Account
            if (choice1.equalsIgnoreCase("B")) { 
                System.out.println("How much do you want to withdraw?");
                double amount4 = cin.nextDouble();
                double total4 = savingAccount - amount4;
                System.out.println("You withdrew " + amount4);
                System.out.println("You currently have: " + total4);
            } 
            break;
            
        case "C":
            // Checking Account
            if (choice1.equalsIgnoreCase("A")) {
                System.out.println("Your current balance is: " + checkingAccount);
            } else 
            // Saving Account 
            if (choice1.equalsIgnoreCase("B")) {
                System.out.println("Your current balance is: " + savingAccount);
            }
            break;
        case "E":
            System.out.println("You exited the program.");
            break;
        default:
            System.out.println("Please choose a selction.");
    } 
    
    
}

【问题讨论】：

处理不同大小写的一种简单方法是将所有内容都转换为大写choice = choice.toUpperCase();（它是“小写”而不是“小写”）

标签： java while-loop switch-statement

【解决方案1】：

我会做的

switch(choice2.toUpperCase())

所以你不必担心它们是大写还是小写，但你也可以这样做

case "D": // fall through
case "d":

同一代码块有两种情况。

对于已有的程序，由于都在main函数中，直接返回即可

 case "E":
     System.out.println("You exited the program.");
     return;

【讨论】：