how to read in a text file in c++ code example

Example 1: How to read a file in in C++

// io/read-file-sum.cpp - Read integers from file and print sum.
// Fred Swartz 2003-08-20

#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); // terminate with error
    }
    
    while (inFile >> x) {
        sum = sum + x;
    }
    
    inFile.close();
    cout << "Sum = " << sum << endl; 
    return 0;
}

Example 2: 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 3: write to file in C++

ofstream myfile;
myfile.open("file.txt");

myfile << "write this to file"