c++ - 在 ‘,’ token { (C++)

Question

所以我在编译我的代码时遇到了这个错误(预期的'，'或';'在'{' token {之前)我知道stackoverflow上可能有很多这样的错误，但似乎寻找解决方案:

我是 C++ 的新手。这是代码:我必须从文本文件 (data.txt) 中读取数据并显示它:

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

int main(){

FILE *fptr;
char country[5][20];
int population[5];
int landMass[5];
int option;
int i;
int countryOption;
int gdp[5];
int populationDensity[5];
int gdpHead[5];

//open file for reading
fptr = fopen("data.txt", "r");      

//Error checking
if (fptr == NULL) {                
   printf("Unable to open data.txt");
   return(1);
}

//input from user
printf("Hi welome to the country database!");
getchar();
system("cls");
printf("Select a country for information:\n");
printf("1)Canada\n");
printf("2)Italy\n");
printf("3)China\n");
printf("4)USA\n");
printf("5)Russia\n");
printf("6)All\n");
printf("Type in the option you want:");
scanf("%d", &option);
system("cls");

//reads data from data.txt and assigns to variables
for (i = 1; i <= 5; i++) {
    fscanf(fptr, "%s %d %d %d", country[i], &population[i], &landMass[i], &gdp[i]);
    populationDensity[i] = (population[i]/landMass[i]);
    gdpHead[i] = ((gdp[i]*1000000)/population[i]); 

    if (option == 6) {
        printf("Here is info on all the countries in our database:\n");
        printf("Country: %s\n", country[i]);     
        printf("Population: %d\n", population[i]);
        printf("LandMass: %d\n", landMass[i]);
        printf("GDP: %d\n", gdp[i]);
        printf("Population density: %d\n", populationDensity[i]);
        printf("Population density: %d\n\n\n", gdpHead[i]);  
    }
}       

void countrySelection(int countryOption)
{
     printf("Here is some info on the country you chose:\n");
     printf("Country: %s\n", country[countryOption]);     
     printf("Population: %d\n", population[countryOption]);
     printf("LandMass: %d\n", landMass[countryOption]);
     printf("GDP: %d\n", gdp[countryOption]);
     printf("Population density: %d\n", populationDensity[countryOption]);
     printf("Population density: %d\n\n", gdpHead[countryOption]);  
}

//function that prints the info
if (option < 6) {
   countrySelection(option);
}                   

fclose(fptr);
system("pause");
return(0);

}

data.txt 看起来像这样:

Canada
42000000
9984670
1821000 
Italy
60920000
301230
2013000
China
1351000000
9706961
8227000   
USA
313900000
9826675
15680000
Russia
143000000
17098246
2015000  

有人知道问题出在哪里吗？？？

Answer 1

您正在 main 函数中定义 void countrySelection(int countryOption)，这在 C++ 中是不允许的。

将函数移到主函数之上，它应该可以编译。此外，您还必须将 countrySelection 中使用的变量定义为全局变量，否则该函数无法访问它们。