C++ help
Author
How do I have some one enter a filename and then open that file for input/output in C++?
std::string filename;std::cout << "Enter the file name:" << std::endl;std::getline(std::cin,filename);if (!std::cin) return;std::ifstream input(filename.c_str());Quote:Original post by fishfin
why is there "std::" in front of "cout" is that nesisary for the code to work?
cout is in the namespace std. You can also use cout without the namespace qualifier by writing:
using std::cout;
Avoid the oft-cited but dangerous using namespace std;, which will pollute your global namespace.
In modern C++, all symbols in the Standard C++ Library are placed within the std namespace. This helps minimize name collisions with your own symbols (the SC++L provides a find algorithm, for instance; without a namespace, you'd have to mangle your own function name for something so common).
Author
I got a compiler eror on this line:
if (!std::cin) return;
saying:
return-statement with no value, in function return 'int'
if (!std::cin) return;
saying:
return-statement with no value, in function return 'int'
Quote:Original post by fishfin
I got a compiler eror on this line:
if (!std::cin) return;
saying:
return-statement with no value, in function return 'int'
This code was meant as an example of usage, not code to be copy-pasted. Understand how it works, and rewrite it so it fits in your own program.
Author
#include <iostream>
#include <fstream>
#include <string>
int main()
{
std::string filename, text;
std::cout<<"What is the filename:";
std::getline(std::cin,filename);
std::ofstream file1 (filename.c_str());
std::cin>>text;
std::cout<< text;
}
I tried this and when I ran it nothing happened after I entered the filename, I had already created a file with that name and put some text in it...
#include <fstream>
#include <string>
int main()
{
std::string filename, text;
std::cout<<"What is the filename:";
std::getline(std::cin,filename);
std::ofstream file1 (filename.c_str());
std::cin>>text;
std::cout<< text;
}
I tried this and when I ran it nothing happened after I entered the filename, I had already created a file with that name and put some text in it...
Your code does what you wrote it to do. It opens a file, then reads a word from standard input (not from the file) and writes it back to standard input.
Perhaps you intended to write to the file?
std::cin >> text;
file << text;
Perhaps you intended to write to the file?
std::cin >> text;
file << text;
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