open and read file c++ code example
Example 1: read a file c++
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main () {
string line;
ifstream myfile ("example.txt");
if (myfile.is_open())
{
while ( getline (myfile,line) )
{
}
myfile.close();
}
else cout << "Unable to open file";
return 0;
}
Example 2: opening file in c++
/ fstream::open / fstream::close
#include <fstream>
int main () {
std::fstream fs;
fs.open ("test.txt", std::fstream::in | std::fstream::out | std::fstream::app);
fs << " more lorem ipsum";
fs.close();
return 0;
}
Example 3: How to read a file in in C++
#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;
int main() {
int sum = 0;
int x;
ifstream inFile;
inFile.open("test.txt");
if (!inFile) {
cout << "Unable to open file";
exit(1);
}
while (inFile >> x) {
sum = sum + x;
}
inFile.close();
cout << "Sum = " << sum << endl;
return 0;
}
Example 4: file reading c++
int a, b;
ifstream bd;
myfile.open("file.txt");
if (myfile.is_open())
while (bd >> a >> b)
cout << a << b << endl;
else cout << "ERROR";