如何打印出文件的内容？ C++ 文件流

Question

I am using fstream and C++ and all I want my program to do is to print out to the terminal the contents of my .txt file. It may be simple, but I have looked at many things on the web and I can't find anything that will help me. How can I do this? Here is the code I have so far:

    #include <iostream>
#include <fstream>
using namespace std;

int main() {
    string output;
    ifstream myfile;
    ofstream myfile2;

    string STRING;
    myfile.open ("/Volumes/LFARLEIGH/Lucas.txt");

    myfile2 << "Lucas, It Worked";

        myfile >> STRING;
        cout << STRING << endl;
    myfile.close();


    return 0;
}

Thank you in advance. Please forgive me if this is very simple as I quite new to C++

Answer 1

There's no reason to reinvent the wheel here, when this functionality is already implemented in the standard C++ library.

#include <iostream>
#include <fstream>

int main()
{
    std::ifstream f("file.txt");

    if (f.is_open())
        std::cout << f.rdbuf();
}

Answer 2

#include <iostream>
#include <fstream>

int main()
{
    string name ;
    std::ifstream dataFile("file.txt");
    while (!dataFile.fail() && !dataFile.eof() )
    {
          dataFile >> name ;
          cout << name << endl;
    }

Answer 3

Try this, just modified at some places. You had tried to open a file using extracter (ie, ifstream) but overwriting this file using inserter (ie, ofstream) without opening the file, that ifstream and ofstream were two different classes. so, they don't understand.

#include<iostream>
#include<fstream>

using namespace std;

int main(){

    string output;
    ifstream myfile;
    ofstream myfile2;

    string STRING;
    // output stream || inserting
    myfile2.open ("/Volumes/LFARLEIGH/Lucas.txt");

    myfile2 << "Lucas, It Worked";


    myfile2.close();

    // input stream || extracting

    myfile.open("/Volumes/LFARLEIGH/Lucas.txt");

        myfile >> STRING;
        cout << STRING << endl;
    myfile.close();


   return 0;
}