C错误，双倍预期加倍*

Question

刚开始使用C而我在代码中遇到1个错误：

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

int main()
{
    //declare variables
    double speed = 1.4, hours, totalYards;

    //prompt user to enter amount of hours
    printf("Enter the amount of hours: ");
    scanf("%lf", &hours);

    //calculate amount of yards taken
    totalYards = speed * hours;

    //display result to user
    printf("The total amount of yards is %.2f", &totalYards);

    return 0;
}

，错误是

警告：格式＆＃39;％f＆＃39;期望类型＆＃39; double＆＃39;的参数，但参数2的类型为＆＃39; double *＆＃39; [-Wformat] |

在最后一个printf。

Answer 1

更改

 printf("The total amount of yards is %.2f", &totalYards);

到

  printf("The total amount of yards is %.2f", totalYards);

您传递的是指针对象（类型为double *），但f要求您传递double类型的值。