Read from File
Reading Data from a File in C++
BeginnerTopic: File Handling Programs
C++ Read from File Program
This program helps you to learn the fundamental structure and syntax of C++ programming.
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main() {
// Open file for reading
ifstream inFile("data.txt");
if (inFile.is_open()) {
string line;
cout << "Reading file line by line:" << endl;
while (getline(inFile, line)) {
cout << line << endl;
}
inFile.close();
} else {
cout << "Error: Unable to open file for reading." << endl;
}
// Alternative: Read word by word
ifstream inFile2("data.txt");
if (inFile2.is_open()) {
string word;
cout << "\nReading file word by word:" << endl;
while (inFile2 >> word) {
cout << word << " ";
}
cout << endl;
inFile2.close();
}
return 0;
}Output
Reading file line by line: Hello, World! This is a C++ file handling program. Line 3: Learning file operations. 100 200 300 Reading file word by word: Hello, World! This is a C++ file handling program. Line 3: Learning file operations. 100 200 300
Understanding Read from File
Reading from a file uses ifstream (input file stream). Use getline() to read line by line, or >> operator to read word by word. The >> operator stops at whitespace. Always check if file opened successfully. The file pointer automatically moves forward as you read.
Note: To write and run C++ programs, you need to set up the local environment on your computer. Refer to the complete article Setting up C++ Development Environment. If you do not want to set up the local environment on your computer, you can also use online IDE to write and run your C++ programs.