how to read from a text file in 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: c++ files
#include <iostream>
#include <fstream>
using namespace std;
int main () {
ofstream myfile;
myfile.open ("example.txt");
myfile << "Writing this to a file.\n";
myfile.close();
return 0;
}
Example 3: how to read and write in a file c++
#include <iostream>
#include <fstream>
using namespace std;
ifstream file_variable;
file_variable.open("input.txt");
file_variable.close();
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while (cin >> name >> value)
{
cout << name << value << endl;
}
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ofstream out_file;
out_file.open("output.txt");
out_file << "Write this scentence in the file" << endl;
Example 4: 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 5: read text from file c++
#include<iostream>
#include<fstream>
using namespace std;
int main() {
ifstream myReadFile;
myReadFile.open("text.txt");
char output[100];
if (myReadFile.is_open()) {
while (!myReadFile.eof()) {
myReadFile >> output;
cout<<output;
}
}
myReadFile.close();
return 0;
}
Example 6: c++ read matttrix from text file
ifstream f("matrix.txt");
f >> m >> n;
if ((m != 4) || (n != 3))
{
cout << "Matrix not 4 by 3!n";
return 1;
}
for (int i = 0; i < m; i++)
for (int j = 0; j < m; j++)
f >> A[i][j];