c 无限循环错误

Question

程序构建正确，但我得到了随机数的无限循环，我不确定为什么。我

int getInt(void);
double getDbl(void);
void prnTitle(void);
void prnFooter(double gTotal);
void pause(void);
double getDblLimited(double lowerLimit, double upperLimit);

1. 提交里程碑一时注释掉 main
2. 您的最后一个里程碑应该可以与以下测试程序完美运行。

要注释掉 main()，请删除箭头后面的两个字符

int main (void)
{
    int iVal;
    double dVal;
    welcome();

    // testing prnTitle()
    printf("listing header and footer with grand total:\n");
    prnTitle();



    // Testing prnFooter()
    prnFooter(1234.5678);
    printf("listing header and footer without grand total:\n");
    prnTitle();
    prnFooter(-1);


    // Testing Pause() and clrKyb()
    pause();


    // Testing getInt()
    printf("Enter an integer: ");
    iVal = getInt();
    printf("You entered: %d\n", iVal);


    // Testing Get Int Limited
    printf("Enter an integer between 10 an 20: ");
    iVal = getIntLimited(10, 20);
    printf("Your entered %d\n", iVal);


    // Testing Get Double
    printf("Enter a floating point number: ");
    dVal = getDbl();
    printf("You entered: %0.2lf\n", dVal);


    // Tesing Get Double Limited
    printf("Enter a floating point number between 10.00 an 20.00: ");
    dVal = getDblLimited(10.0, 20.0);
    printf("You entered: %0.2lf\n", dVal);



    printf("End of tester program for milestone one!\n");
    return 0;
    }


/* End Commenting out the main out*/

// implement your functions for milestone one down here:
void welcome(void)
{
    printf("---=== Grocery Inventory System ===---\n");

}

void prnTitle(void)
{
    printf("Row |SKU| Name \t | Price |Taxed| Qty | Min |  Total  |Atn \n");
    printf("----+---+--------------------+--------+-----+-----+-----+------------+|---\n");

}
void prnFooter(double gTotal)
{
    printf("--------------------------------------------------------+-----------------\n");
    //float  gTotal = 1234.57;
    while (gTotal > 0)
    {
        printf("%12.21f", gTotal);
    }
}
void clrKyb(void)
{
    char b;
    while (b != '\n')
    {
        scanf("%c", &b);
    }

}
void pause(void)
{
    printf("Press <Enter> to continue...");

    clrKyb();

}
int getInt(void)
{
    //printf("Enter an interger:");
    int d;
    char c;
    scanf("%d%c", &d, &c);
    while (c != '\n')
    {
        printf("Invalid integer, please try again ");
        scanf("%d%c", &d, &c);
    }
    return d;
}
int getIntLimited(int lowerLimit, int upperLimit)
{
    int a;
    //printf("Enter an integer between %d and %d:", lowerLimit, upperLimit);
    scanf("%d", &a);
    while (a <= lowerLimit || a >= upperLimit)
    {
    //  printf("Invalid value, %d < value < %d:", lowerLimit, upperLimit);
        scanf("%d", &a);
    }
    return a;
}
double getDbl(void)
{
    double d;
    char c;
//  printf("Enter a floating point number:");
    scanf("%lf,%c", &d, &c);
    while (c != '\n')
    {
        printf("Invalid number, please try again ");
        scanf("%lf%c", &d, &c);
    }
    return d;
}

double getDblLimited(double lowerLimit, double upperLimit)
{
    double a;
    printf("Enter a floating point number between %f and %f:", lowerLimit, upperLimit);
    scanf("%lf", &a);
    while (a <= lowerLimit || a >= upperLimit)
    {
        printf("Invalid value, %f < value < %f:", lowerLimit, upperLimit);
        scanf("%lf", &a);

    }
    return a;
    return 0;
}

Answer 1

void prnFooter(double gTotal)
{
    printf("--------------------------------------------------------+-----------------\n");
    //float  gTotal = 1234.57;
    while (gTotal > 0)
    {
        printf("%12.21f", gTotal);
    }
}

您永远不会在循环内修改gTotal 的值。如果进入循环时它大于 0，它将永远大于 0，从而进入无限循环。