Here is an example C++ program that reads data from a CSV file, stores it in an array, performs some manipulation, and writes the result to a text file:
#include #include #include #include #include using namespace std; int main() { // Open CSV file for reading ifstream inputFile("data.csv"); // Check if file opened successfully if (!inputFile.is_open()) { cout << "Error: could not open file." << endl; return 1; } // Read data from CSV file vector<vector> data; string line; while (getline(inputFile, line)) { stringstream ss(line); vector row; string value; while (getline(ss, value, ',')) { row.push_back(stod(value)); } data.push_back(row); } // Close CSV file inputFile.close(); // Perform some manipulation on data for (int i = 0; i < data.size(); i++) { data[i][0] += 1.0; data[i][1] *= 2.0; } // Open output file for writing ofstream outputFile("result.txt"); // Check if file opened successfully if (!outputFile.is_open()) { cout << "Error: could not open file." << endl; return 1; } // Write manipulated data to output file for (int i = 0; i < data.size(); i++) { for (int j = 0; j < data[i].size(); j++) { outputFile << data[i][j] << " "; } outputFile << endl; } // Close output file outputFile.close(); return 0; }
In this example, the CSV file to be read is named data.csv
, and the output file to be written is named result.txt
. The program reads the CSV data into a vector of vectors, where each inner vector represents a row of the CSV data. The program then performs some manipulation on the data (adding 1 to the first column and multiplying the second column by 2), and writes the manipulated data to the output file in text format, with each row separated by a newline character.