Question

c语言调用void函数

#include<stdio.h>
#include<math.h>
void equation(double a,double b,double c);
int main(){
int a,b,c;
printf("Input the a:");
scanf("%d",&a);
printf("Input the b:");
scanf("%d",&b);
printf("Input the c:");
scanf("%d",&c);
void equation(double a,double b,double c);
return 0;
}
void equation(double a,double b,double c){
double d,x1,x2;
d=b*b-4*a*c;
if(d>0){
x1=((-b)+sqrt(d))/(2.0*a);
x2=((-b)-sqrt(d))/(2.0*a);
printf("x1=%.2f,x2=%.2f\n",x1,x2);
}
if(d==0){
x1=((-b)+sqrt(d))/(2.0*a);
printf("x1=%.2f\n",x1);
}
if(d<0){
printf("无实根\n");
}
return;

}
任务要求调用void函数，为什么输入a,b,c的值后没有输出任何语句就结束了？d的判断已经包括了全部情况为什么没有输出?

Answer 1

你在main函数中的这一行语句void equation(double a,double b,double c);是函数的声明不是调用改为equation(a,b,c);就行了

Answer 2

main函数中void equation(double a,double b,double c);改为
equation(a,b,c); // 函数调用
void equation(double a,double b,double c);是声明
将void equation(double a,double b,double c);改为void equation(int a,int b,int c);