Function return nothing with multiple files? - c++

Question

When I run one file, it works perfectly. Then I separate 3 file: header, main, function from that file. It aslo works but return nothing. Here the code:
File Header: printStudent.h
//Header.h
#ifndef PRINTSTUDENT_H_INCLUDED
#define PRINTSTUDENT_H_INCLUDED
void read ();
#endif
File Function: readFileCSV.cpp . It read and print from my .csv file
#include <iostream>
#include <fstream>
#include <iomanip>
#include <string.h>
#include <algorithm>
#define student 1000
using namespace std;
void read (){
ifstream readFileCSV;
readFileCSV.open("studentEn.csv");
if(!readFileCSV.is_open()) {cout << "ERROR: File can't be opened or it doesn't exist" << endl;};
string aMSSV[student];
string aname[student];
string abirthDay[student];
string aaddress[student];
string MSSV;
string name;
string birthDay;
string address;
int countStudent = 0;
while(readFileCSV.good()) {
getline(readFileCSV, MSSV, ',');
getline(readFileCSV, name, ',');
getline(readFileCSV, birthDay, ',');
getline(readFileCSV, address, '\n');
int lengthAddress = address.length();
char charAddress[lengthAddress];
strcpy(charAddress, address.c_str());
char newCharAddress[lengthAddress-2];
for(int i = 0 ; i < lengthAddress-2 ; i++){
newCharAddress[i] = charAddress[i+1];};
string address(newCharAddress, lengthAddress - 2);
aMSSV[countStudent] = MSSV;
aname[countStudent] = name;
abirthDay[countStudent] = birthDay;
aaddress[countStudent] = address;
countStudent ++;
};
countStudent = countStudent - 1;
cout << "..................................................STUDENT..........................................................." << endl;
cout << setw(5) << left << "STT";
cout << setw(25) << left << "MSSV";
cout << setw(25) << left << "Name";
cout << setw(25) << left << "Date of Birth";
cout << left << "Address";
cout << endl;
cout << "...................................................................................................................." << endl;
for(int i = 0 ; i < countStudent ; i++){
cout << setw(5) << left << i + 1;
cout << setw(25) << left << aMSSV[i];
cout << setw(25) << left << aname[i];
cout << setw(25) << left << abirthDay[i];
cout << left << aaddress[i];
cout << endl;
}
readFileCSV.close();
}
File main:
#include <iostream>
#include "printStudent.h"
using namespace std;
int main(){
void read ();
return 0;
}
Help me why it's return nothing and give me a solution how can i make it works? Thanks!

Answer 1

int main(){
void read ();
return 0;
}
It is a function declaration in main a.k.a. forward declaration. Any expression that starts with a type or void is a declaration. It is a local declaration, thus it doesn't conflict with the globally declared function read.
To call the function do it so
int main(){
read ();
return 0;
}