c - C 中的变量乘法？

Question

//Hydroelectric Dam Helper
#include <stdio.h>
#define GRAV 9.80
#define EFINC 0.9
#define EFINC2 90


int main()
{
  //Defines all the variables to be used
  double height, work, mass;
  printf("Height of dam (in meters):");
  scanf("%lf", &height);
  printf("Flow of water (in thousand cubic meters per second):");
  scanf("%lf", &mass);
  work = (mass * GRAV * height * EFINC); 
  printf("The dam would produce %f megawatts at %d%% efficency", &work, EFINC2);
  return 0; 
}

值设置正确，我通过打印高度和质量来测试它，但 work 从未收到值，EFINC2 打印出一个我不太确定的荒谬数字

Answer 1

printf("The dam would produce %f megawatts at %d%% efficency", &work, EFINC2);

应阅读:

printf("The dam would produce %f megawatts at %d%% efficency", work, EFINC2);

&work 是指向工作的指针，即 double* 但要让 printf 打印您需要传递的值 double 而不是指针。在您的平台上，double* 可能与 double 大小不同，导致后续 printf 格式使用错误数据。