我如何从文件C ++读取并输出它

Question

I tried to use getline

but it give me some error

note: __ssize_t getline(char**, size_t*, FILE*)

My line is like this

ofstream myfile;

myfile.open("file.txt");
while(!myfile.eof())
{
    getline(myfile,sline);
    cout << sline;
 }

How do i get my C++ to read file.txt

Answer 1

Ensure you have #include <string> , where std::getline() is defined, and that sline is a std::string .

Change the structure of the loop to:

while (std::getline(myfile, sline))
{
    std::cout << sline << "\n";
}

to avoid processing a failed read.

Use std::ifstream to read, not std::ofstream as pointed out by Karoly in the comments.

Answer 2

It looks like you #include d <stdio.h> or <cstdio> and are therefore trying to use C's getline function. Change:

getline(myfile,sline);

to:

std::getline(myfile,sline);

to ensure that you are using the C++ getline .