根据用户输入打开文件c ++ [英] opening a file based on user input c++

问题描述

我正在尝试制作一个程序，该程序将根据用户输入打开文件.这是我的代码:

I am trying to make a program that would open a file based on the users input. Here`s my code:

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

int main() {

    string filename;
    ifstream fileC;

    cout<<"which file do you want to open?";
    cin>>filename;

    fileC.open(filename);
    fileC<<"lalala";
    fileC.close;

    return 0;
}

但是当我编译它时，它给了我这个错误:

But when I compile it, it gives me this error:

[Error] no match for 'operator<<' (operand types are 'std::ifstream {aka std::basic_ifstream<char>}' and 'const char [7]')

有人知道如何解决这个问题吗?谢谢...

Does anyone know how to solve this? Thank you...

推荐答案

您的代码有几个问题.首先，如果要写入文件，请使用 ofstream . ifstream 仅用于读取文件.

Your code has several problems. First of all, if you want to write in a file, use ofstream. ifstream is only for reading files.

第二，open方法使用一个 char [] ，而不是一个 string .在C ++中存储字符串的常用方法是使用 string ，但是它们也可以存储在 char s数组中.要将 string 转换为 char [] ，请使用 c_str()方法:

Second of all, the open method takes a char[], not a string. The usual way to store strings in C++ is by using string, but they can also be stored in arrays of chars. To convert a string to a char[], use the c_str() method:

fileC.open(filename.c_str());

close 方法是一个方法，而不是属性，因此需要括号: fileC.close().

The close method is a method, not an attribute, so you need parentheses: fileC.close().

因此正确的代码如下:

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

int main() {
    string filename;
    ofstream fileC;

    cout << "which file do you want to open?";
    cin >> filename;

    fileC.open(filename.c_str());
    fileC << "lalala";
    fileC.close();

    return 0;
}

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