问题描述

（c语言）利用%ld读取double类型，程序可以运行，但是结果是很大的负数？

#include
#define TAX_1 17850
#define TAX_2 23900
#define TAX_3 29750
#define TAX_4 14875
#define TAXRATE_1 0.15
#define TAXRATE_2 0.28
int main(void)
{
double taxsalary,taxpay;
int n;
printf("Please enter your taxsalary(q to quit):n");
while(scanf("%ld",&taxsalary)==1)
{
printf("please enter your kinds of tax(from 1 to 4):n");
printf("1)single tax: $17850 %15 more:%28n");
printf("2)owner tax: $23900 %15 more:%28n");
printf("3)double(together) tax: $29700 %15 more:%28n");
printf("4)double(divorce) tax: $23900 %15 more:%28n");
scanf("%d",&n);
if (n==1)
{
if(taxsalary<=TAX_1)
{
taxpay=taxsalary*TAXRATE_1;
printf("taxpay:%ldn",taxpay);

            }

        else
          {
            taxpay=TAX_1*TAXRATE_1+(taxsalary-TAX_1)*TAXRATE_2;
                printf("taxpay:%ldn",taxpay);
          }

    }
    if (n==2)
    {
        if (taxsalary<=TAX_2)
        {
            taxpay=taxsalary*TAXRATE_1;
                printf("taxpay:%ldn",taxpay);
        }
        else
        {
            taxpay=TAX_2*TAXRATE_1+(taxsalary-TAX_2)*TAXRATE_2;
            printf("taxpay:%ldn",taxpay);
        }

    }
    if (n==3)
    {
        if (taxsalary<=TAX_3)
        {
            taxpay=taxsalary*TAXRATE_1;
                printf("taxpay:%ldn",taxpay);
        }
        else
        {
            taxpay=TAX_3*TAXRATE_1+(taxsalary-TAX_3)*TAXRATE_2;
                printf("taxpay:%ldn",taxpay);
        }

    }
    if (n==4)
    {
        if (taxsalary<=TAX_4)
        {
            taxpay=taxsalary*TAXRATE_1;
                printf("taxpay:%ldn",taxpay);
        }
        else
        {
            taxpay=TAX_4*TAXRATE_1+(taxsalary-TAX_4)*TAXRATE_2;
                printf("taxpay:%ldn",taxpay);
        }
    }
    printf("Please enter your taxsalary:(q to quit)n");

}
return 0;

}

解决方案

非常感谢，又仔细查了一下。是%lf，记错了，

解决方案二：

%ld, 应该是读取long吧，double不是应该%lf?