通過引用傳遞與C不同的C？

Question

我剛剛得到這個，當我嘗試運行它 error: expected ‘;’, ‘,’ or ‘)’ before ‘&’ token

它在抱怨這條線

int read_values(double &sum) { 

，所以我想通過總和，然後直接編輯。你如何在C中做到這一點？多謝你們。

#include <stdio.h> 

/* 
    Read a set of values from the user. 
    Store the sum in the sum variable and return the number of values read. 
*/ 
int read_values(double &sum) { 
    int values=0,input=0; double sum2=0; 
    sum2 = sum; 
    printf("Enter input values (enter 0 to finish):\n"); 
    scanf("%d",&input); 
    printf("%d\n", input); 
    while(input != 0) { 
    values++; 
    sum2 += input; 

    scanf("%d",&input); 
    } 

    return values; 
} 

int main() { 
    double sum=0; 
    int values; 
    values = read_values(sum); 
    printf("Average: %g\n",sum/values); 
    return 0; 
} 

Answer 1

C不做引用，只有原始指針。

main() { 
    ... 
    values = read_values(&sum); 
    ... 
} 


int read_values(double* sum) 
{ 
    ... 
    sum2 = *sum; 
    ... 

} 

Answer 2

我想你想做到這一點：

int read_values(double *sum) { 
    int values=0,input=0; 
    printf("Enter input values (enter 0 to finish):\n"); 
    scanf("%d",&input); 
    printf("%d\n", input); 
    while(input != 0) { 
    values++; 
    *sum += input; 
    scanf("%d",&input); 
    } 
    return values; 
} 

int main() { 
    double sum=0; 
    int values; 
    values = read_values(&sum); 
    printf("Average: %g\n",sum/values); 
    return 0; 
}