Read from a file to three parallel array - c++

Question

As part of my assignment I need to open a file and then read the information into 3 arrays. These information are separated into 3 different columns first one is, Country Code name(is string), second is the population(is int) and the third is the full name of the country. Here is the example of few lines of the file:
AU 20090437 Australia
BR 186112794 Brazil
BU 7262675 Bulgaria
CA 32805041 Canada
CN 1306313812 China
DO 8950034 Dominican Republic
So far I have:
void readCntrData(string [], int [], string[], int &size, const int maxSize);
int main()
{
const int COUNTRIES = 200;
// maximum size of arrays
int size = 0;
string cntrCodes[COUNTRIES];
int cntrPopulation[COUNTRIES];
string cntrNames[COUNTRIES];
string inputFileName = "countries.txt";
ifstream inputFile;
inputFile.open(inputFileName.c_str());
if (inputFile.fail())
{
cout << "\n\tPlease check the name of the input file and \n\ttry again later!\n";
exit(EXIT_FAILURE);
}
int index = 0;
while (index < COUNTRIES && inputFile >> cntrCodes[index] >> cntrPopulation[index] >> cntrNames[index] ) {
index++;
}
size = index;
if (size == COUNTRIES && !inputFile.eof()){
cout << "\n\tThe input file \"" << inputFileName <<
"\"is too big: \n\tit has more than " << COUNTRIES << " items!\n";
exit(EXIT_FAILURE);
}
inputFile.close();
}
The issue here few countries have two part names, and my code breaks where the name of country has two parts. I don't know how to ignore the space there and read the whole name.
I appreciate any feedback.

Answer 1

Just cleaning the code up a bit...
the main problem you ask about in your question has already been addressed by user4581301 in comments: summarily, using getline to read the country code will cope with having one or more whitespace-separated words
since C++11, we've been able to use the ifstream constructor to open a filename passed in a std::string, and it's often convenient to construct the ifstream inside an if/else construct that then handles the successful-open and failed-attempt-to-open cases
there's no need to explicitly close ifstreams that are going out of scope anyway
it's good to send error messages to std::cerr, so if someone running your program does something like "theprogram > theprogram.output" they'll still see the error messages in their terminal
no real need to have separate index and size variables, and something like num_countries is a better, more meaningful name
checking for EOF is a bit of a dark art - I wouldn't recommend using inputFile.eof() the way you did because if the last country read was followed by an empty line in the file, you wouldn't have hit end-of-file even though it's "logically" empty thereafter; it's too easy for someone not to notice empty lines at the end of a file when they're working in a editor to create/update the file; checking if there's another non-whitespace character is a more robust approach
the common size for int these days is 32 bits, which can handle numbers up to a couple billion (when signed, or a bit over 4 billion for unsigned int); China's population's a bit too close to that for comfort - if you want to write code in a way that should still work 20 or 50 years hence, it's good to think about whether the types will still be large enough to store the values; int64_t from <cstdint> is a better choice.
Revised code:
int main()
{
const int COUNTRIES = 200;
string cntrCodes[COUNTRIES];
int64_t cntrPopulation[COUNTRIES];
string cntrNames[COUNTRIES];
string inputFileName = "countries.txt";
if (std::ifstream inputFile{inputFileName})
{
int num_countries = 0;
while (num_countries < COUNTRIES &&
inputFile >> cntrCodes[num_countries] >> cntrPopulation[num_countries] &&
getline(std::cin, cntrNames[num_countries]))
++num_countries;
// will see if we can read another character (remember >> skips
// whitespace by default), rather than check inputFile.eof()
// which may not be true if there're any extra empty lines after
// the data...
char character;
if (num_countries == COUNTRIES && inputFile >> character)
{
std::cerr << "\n\tThe input file \"" << inputFileName <<
"\"is too big: \n\tit has more than " << COUNTRIES << " items!\n";
exit(EXIT_FAILURE);
}
// any extra code to actually use the country data goes here...
}
else
{
std::cerr << "\n\tPlease check the name of the input file and \n\ttry again later!\n";
exit(EXIT_FAILURE);
}
}

Answer 2

For the last input of each line, you can use getline which reads everything until it meets an Enter key.
You can try this:
while (index < COUNTRIES && inputFile >> cntrCodes[index] >> cntrPopulation[index] ) {
getline (inputFile, cntrNames[index]);
index++;
}