c++ - 将自定义字符串放入文件中

Question

我想在现有文件的末尾添加一个新行(字符串)。但它没有用。这是代码:

    #include <iostream>
    #include <fstream>
    #include <cstdlib>
    #include <string>

    using namespace std;

int main()
{
    ifstream input("Sample.ini");
    ofstream output("Sample.ini",ios::app);

    cout << "Lines that have existed in file:" << endl;

    while (input) // Print out the existed line
    {
        string newstring;
        getline(input,newstring);
        cout << newstring << endl;
    }

    cout << "Line you want to add:" << endl;

    string outputstring;
    getline(outputstring,output); // get the whole line of outputstring,
                                  // and deliver it into output file
    return 0;
}

第一个将文件中的行读取为字符串的 getline 效果很好。但是，第二个，不是。编译器返回如下:

...\file test.cpp|35|error: no matching function for call to 'getline(std::istream&, std::ofstream&)'|

Answer 1

你写了太多代码。你只需要两行:

ofstream output("Sample.ini",ios::app);
output << outputstring;