Loop iteration issue c++ - c++

Question

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <fstream>
#include <vector>
#include <sstream>
using namespace std;
int main()
{
string line;
ifstream infile ("Input.csv");
vector<string> table;
string word;
if(infile.is_open())
{
getline(infile,line);
istringstream iss(line);
while(!iss.eof())
{
getline(iss,word, ',');
table.push_back(word);
}
}
for(int index=0; index<11; ++index)
{
cout<< "Element" << index << ":" << table.at(index) << endl ;
}
infile.close();
}
In the above program I am reading values from input file and splitting based on comma and finally storing the values into a vector.
when I print vector I am able to view only the first line of input file.
Input file:
CountryCode,Country,ItemCode,Item,ElementGroup,ElementCode,Element,Year,Unit,Value,Flag
100,India,3010,Population - Est. & Proj.,511,511,Total Population - Both sexes,1961,1000,456950,
100,India,3010,Population - Est. & Proj.,511,511,Total Population - Both sexes,1962,1000,466337,
100,India,3010,Population - Est. & Proj.,511,511,Total Population - Both sexes,1963,1000,476025,
100,India,3010,Population - Est. & Proj.,511,511,Total Population - Both sexes,1964,1000,486039,
Output:
Element0:CountryCode
Element1:Country
Element2:ItemCode
Element3:Item
Element4:ElementGroup
Element5:ElementCode
Element6:Element
Element7:Year
Element8:Unit
Element9:Value
Element10:Flag
Problem: Only 1st line is being printed

Answer 1

I suggest rewriting it like this:
int main()
{
string line;
ifstream infile ("Input.csv");
vector<string> table;
string word;
while(getline(infile, line))
{
istringstream iss(line);
while(getline(iss,word, ','))
{
table.push_back(word);
}
}
for(int index=0; index<11; ++index)
{
cout<< "Element" << index << ":" << table.at(index) << endl ;
}
infile.close();
}
The stream will return false from getline and most other operations whenever it is invalid. So if it didn't open, the while loop won't run. And when it reaches EOF, the while loop will stop. Much simpler to read this way I think.

Answer 2

You have several issues, addressed below:
int main()
{
std::string line;
std::ifstream infile ("Input.csv");
std::vector<std::string> table;
while (std::getline(infile, line)) // this is the loop you want to read the file
{
std::istringstream iss(line);
std::string word;
while (std::getline(iss, word, ',')) // there are better ways to do this, but this will work
{
table.push_back(word);
}
}
for(int index=0; index<table.size(); ++index) // loop through the whole size
{
std::cout<< "Element" << index << ":" << table[index] << std::endl ;
}
infile.close();
return 0;
}
Alternatively, you can avoid the use of nested while loops altogether:
struct csv_reader : std::ctype<char>
{
csv_reader() : std::ctype<char>(get_table()) {}
static std::ctype_base::mask const* get_table()
{
static std::vector<std::ctype_base::mask> rc(table_size, std::ctype_base::mask());
rc['\n'] = std::ctype_base::space;
rc[','] = std::ctype_base::space;
return &rc[0];
}
};
int main()
{
std::string line;
std::ifstream infile ("Input.csv");
csv_reader reader;
infile.imbue(std::locale(std::locale(), &reader);
std::vector<std::string> table{std::istream_iterator<std::string>(infile), std::istream_iterator<std::string>()};
// or
//std::vector<std::string> table;
//std::copy(std::istream_iterator<std::string>(infile), std::istream_iterator<std::string>(), std::back_inserter(table));
for(int index=0; index<table.size(); ++index) // loop through the whole size
{
std::cout<< "Element" << index << ":" << table[index] << std::endl ;
}
infile.close();
return 0;
}

Answer 3

You read only one line of the file
if(infile.is_open())
{
getline(infile,line);
istringstream iss(line);
while(!iss.eof())
{
getline(iss,word, ',');
table.push_back(word);
}
}
If you need to read all lines of the file then you can write instead
while (getline(infile,line))
{
istringstream iss(line);
while(!iss.eof())
{
getline(iss,word, ',');
table.push_back(word);
}
}

Answer 4

You only read the first line.
Add a loop with a condition like
while (getline(infile, line)) {
...
}

Answer 5

Your for loop only print the first 11 posts from the array.
You should it to the lenght of the array.
Not sure what the syntax is for c++ for length of the table but that should be the issue.
for(int index=0; index<table.size(); ++index)
{
cout<< "Element" << index << ":" << table.at(index) << endl ;
}