Directing output into a .txt file in C++ - c++

Question

How do I direct the output of this code into a .txt file?
#include <iostream>
#include <vector>
#include <string>
#include <fstream>
using namespace std;
int main() {
using std::cin;
using std::cout;
using std::endl;
int input=1;
int sum=0;
int counter=1;
while (input != 0)
{
std::cout << "Please enter the hit data: ";
std::cin >> input;
if (input == 0) // after puting in data input zero
{
break;
}
else if (input != 0)
{
sum += input;
counter++;
}
}
counter = counter - 1 ;
std::cout << "Sum of hits entered: " << sum << endl ;
std::cout << "Number of hits entered: " << counter << endl ;
if ( counter < 100 )
{
std::cout << "The hits are less than 100" ;
}
else if ( counter > 100 )
{
std::cout << "The hits are greater than 100" ;
}
else if ( counter == 100 )
{
std::cout << "The hits are equal to 100" ;
}
}
Also, instead of a user having to input data, how can I get the program to read data from another .txt file? I understand you can do this all easily in the terminal; however, I would like for the program to create the .txt file.
Also, how do I get the program to recognize certain numbers? I want it to output something like "there was twelve number -11s counted".

Answer 1

Use std::ifstream to read input from a file, and std::ofstream to write output to a file. For example:
#include <iostream>
#include <fstream>
int main()
{
int sum = 0;
int counter = 0;
std::ifstream in("hits.txt");
if (in.is_open())
{
while (in >> input)
{
sum += input;
++counter;
}
}
else
{
std::ofstream out("hits.txt");
int input;
do
{
std::cout << "Please enter the hit data: ";
// after putting in data, input zero
if (!(std::cin >> input) || (input == 0))
break;
out << input << " ";
sum += input;
++counter;
}
while (true);
}
std::cout << "Sum of hits entered: " << sum << endl ;
std::cout << "Number of hits entered: " << counter << endl ;
if (counter < 100)
{
std::cout << "The hits are less than 100" << std::endl;
}
else if (counter > 100)
{
std::cout << "The hits are greater than 100" << std::endl;
}
else
{
std::cout << "The hits are equal to 100" << std::endl;
}
return 0;
}
Also, how do I get the program to recognize certain numbers? I want it to output something like "there was twelve number -11s counted".
You can use std:map for that, eg:
#include <iostream>
#include <fstream>
#include <map>
int main()
{
int sum = 0;
int counter = 0;
std::map<int, int> hits; // hit counter
std::ifstream in("hits.txt");
if (in.is_open())
{
while (in >> input)
{
hits[input]++;
sum += input;
++counter;
}
}
else
{
std::ofstream out("hits.txt");
int input;
do
{
std::cout << "Please enter the hit data: ";
// after putting in data, input zero
if (!(std::cin >> input) || (input == 0))
break;
out << input << " ";
hits[input]++;
sum += input;
++counter;
}
while (true);
}
std::cout << "Sum of hits entered: " << sum << endl ;
std::cout << "Number of hits entered: " << counter << endl ;
if (counter < 100)
{
std::cout << "The hits are less than 100" << std::endl;
}
else if (counter > 100)
{
std::cout << "The hits are greater than 100" << std::endl;
}
else
{
std::cout << "The hits are equal to 100" << std::endl;
}
for (auto &p : hits)
{
if (p.second == 1)
std::cout << "there was 1 number " << p.first << " counted" << std:::endl;
else
std::cout << "there were " << p.second << " number " << p.first << "'s counted" << std:::endl;
}
/* or, if you are not using C++11 or later:
for (std::map<int, int>::iterator iter = hits.begin(); iter != hits.end(); ++iter)
{
std::map<int, int>::value_type &p = *iter;
if (p.second == 1)
std::cout << "there was 1 number " << p.first << " counted" << std:::endl;
else
std::cout << "there were " << p.second << " number " << p.first << "'s counted" << std:::endl;
}
*/
return 0;
}

Answer 2

Outputting data to a .txt file is easy indeed. You already included , now you need to create an object from the type std::ofstream and use it to write your text into a file. I would create a function like this (above main):
#include <iostream>
#include <fstream>
#include <string>
void outputTextToFile (std::string p_text) {
//is created under your project filepath:
std::ofstream file("nameoffile.txt", std::ios::app); //"app" = appending, instead of overwriting text
file << "Writing this to a file.\n";
file.close();
}
Afterwards you can call your function in the while loop with the string text you want, like this for example:
outputTextToFile("test Text");
Reading text from a .txt file is very similar to this, I would suggest you look up this thread: Read file line by line