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.
#include <iostream> #include <fstream> using namespace std; int main() { ofstream outfile("outfile.txt"); outfile << "Lookit me! I'm in a file!" << endl; int x = 200; outfile << x << endl; outfile.close(); 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.