Lecture Preview: Streams

(Suggested book reading: Programming Abstractions in C++, Chapters 3-4)

Today we will learn about the C++ stream objects that perform input and output (called "I/O") from the console or files. Here is an example of using a stream to read a file and print its contents:

#include <fstream>
#include <iostream>
#include <string>
#include "console.h"
using namespace std;

int main() {
    // read and print every line of a file
    ifstream input;
    input.open("poem.txt");
    string line;
    while (getline(input, line)) {
        cout << line << endl;
    }
    input.close();
    return 0;
}

This code uses two different stream objects:

  1. input is an input file stream, or ifstream.
  2. And you already know about cout, which does console output.
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