Question

嘿伙计们我正在构建一个ATM程序，我一切都很好

我有拉出的菜单，你可以选择一个选项，它运行的功能如何，我不能为我的生活

设定平衡点让它留下来，直到它改变并且我需要它保存一旦它在两个选项之一（存款，撤销）中发生变化，因为这是一个后测试循环，它将一直持续到选择退出并且每次我需要它来更新余额时。

这是我的C代码，如果有人可以帮助那将是惊人的。

#include <stdio.h>
#include <stdlib.h>

// Function Declarations

    int getChoice ();
    double withdraw (int Choice, int Balance);
    double deposit (int Choice, int Balance);
    int VBalance (int Choice, int Balance);
    double process (int Choice, int Balance);



int main (void)
{
// Local Declarations

    int Choice;
    int Balance;


// Statements

do
{
    Balance = 2500.00;
    Choice = getChoice ();
    process (Choice, Balance);
}
while (Choice != 0);


return 0;





} // Main

/*============================process=*/

double process (int Choice, int Balance)
{
// Declarations


// Statements
    switch(Choice)
        {
            case 1: withdraw (Choice, Balance);
                break;
            case 2: deposit (Choice, Balance);
                break;
            case 3: VBalance (Choice, Balance);
                break;
            case 0:  exit;
                break;
            deafult: printf("Sorry Option Not Offered");

} // switch

return 0;
}


/*============================getChoice=*/

int getChoice (void)
{
// Local Declarations
    char Choice;

// Statements

    printf("\n\n**********************************");
    printf("\n             MENU             ");
    printf("\n\t1.Withdrawl Money          ");
    printf("\n\t2.Deposit Money           ");
    printf("\n\t3.View Balance            ");
    printf("\n\t0.Exit                    ");
    printf("\n**********************************");
    printf("\nPlease Type Your Choice Using 0-3");
    printf("\nThen Hit Enter: ");
    scanf("%d", &Choice);

return Choice;

} //getchoice


/*============================withdraw=*/


double withdraw (int Choice, int Balance)
{
// Local Declarations
    double amount;


// Statements
    printf("Funds:%d", &Balance);
    printf("\nPlease Enter How Much You Would Like To Withdraw: ");
    scanf("%f", &amount);
    Balance = Balance - amount;

return Balance;

}  //withdraw


/*============================Deposit=*/

double deposit (int Choice, int Balance)
{
// Local Declarations
    double amount;

// Statements
    printf("Funds:%d", &Balance);
    printf("\nPlease Enter How Much You Would Like To Deposit: ");
    scanf("%f", &amount);
    Balance = Balance + amount;

return Balance;

} //Deposit


/*============================VBalance=*/

int VBalance (int Choice, int Balance)
{
// Statements
    printf("\nYour Current Funds:%d", &Balance); 
    printf("\nThank Your For Viewing");

return 0;
}

Answer 1

首先：启用编译器警告。如果您使用gcc，请在命令行中添加-Wall。如果您使用IDE，则打开警告的选项应该在编译器设置中。

当您使用警告进行编译时，您会发现使用printf和scanf时遇到一些问题。修复那些！

接下来，您遇到Balance main未获得更新的问题。 C使用call by value，这意味着您对函数参数所做的更改在调用函数中不可见。要解决这个问题，您可以将balance参数声明为指针并传递Balance的地址。或者您可以返回新的Balance，就像您在代码中一样。您唯一忘记的是将新值存储到Balance中的main。

更改main中的行：

Balance = process(Choice, Balance);

更改了process：

double process(int Choice, int Balance)
{
    // Declarations

    // Statements
    switch (Choice)
        {
            case 1: Balance = withdraw(Choice, Balance); // Changed line
                break;
            case 2: Balance = deposit(Choice, Balance); // Changed line
                break;
            case 3: Balance = VBalance(Choice, Balance); // Changed line
                break;
            case 0:  exit;
                break;
            deafult: printf("Sorry Option Not Offered");

    } // switch

    return Balance;  // Changed line
}

第三：Balance被声明为int，但您有时会使用double。你应该选择一种类型并坚持下去。由于nature of floating point numbers，实际上建议使用integral type is used for money。

为我的C ATM设置余额

1 个答案: