C++ All-in-One For Dummies, 4th Edition
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Writing to a file is easy in C++. You’re probably already familiar with how you can write to the console by using the cout object, like this:

cout << "Hey, I'm on TV!" << endl;

Well, guess what! The cout object is a file stream! Amazing! And so, if you want to write to a file, you can do it the same way you would with cout:. You just use the double-less-than symbol, called the insertion operator, like this: <<.

If you open a file for writing by using the ofstream class, you can write to it by using the insertion operator. The FileWrite01 example shown demonstrates how to perform this task.

using namespace std;
int main()
    ofstream outfile("outfile.txt");
    outfile << "Lookit me! I'm in a file!" << endl;
    int x = 200;
    outfile << x << endl;
    return 0;

The first line inside the main() creates an instance of ofstream, passing to it the name of a file called outfile.txt.

You then write to the file, first giving it the string, Lookit me! I'm in a file!, then a newline, then the integer 200, and finally a newline. And after that, show the world what a good programmer you are by closing your file.

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John Paul Mueller has written more than 100 books and more than 600 articles on topics ranging from functional programming techniques to application development using C++.

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