THINK++ — Engineering Visualized

Data Input

Reading from Files

Using the ifstream class to read data from the disk back into your program.

WORD BY WORD

ifstream inFile("data.txt");
string word;
while (inFile >> word) {
    cout << word << endl;
}
inFile.close();

LINE BY LINE

string line;
while (getline(inFile, line)) {
    cout << line << endl;
}

EOF CHECK

The loop while(inFile >> x) automatically stops when it hits the End of File (EOF).

FILE MISSING

If the file doesn't exist, is_open() will return false. Always check this first!

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