Beginner with cpp and h files - help

[MiloCharmingMagician]

Hey, I'm new here, and I'm learning C++ you help me if this right?, is it professional?
BTW I'm using, Visual Studio 2017 win32 debug

main.cpp

#include <iostream>
#include <string>
#include "core_text.h"
using namespace std;

int main()
{
	string xs;
	xs = input("Input:");
	print(xs);
	system("pause");
	return 0;
}

core_text.h

#include <iostream>
#include <string>
using namespace std;
#ifndef CORE_TEXT_H
#define CORE_TEXT_H
int print(string msg);
int write(string msg);
string input(string msg);
#endif 

core_text.cpp

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

int print(string msg) {
	cout << msg << endl;
	return 0;
}

int write(string msg) {
	cout << msg;
	return 0;
}

string input(string msg) {
	string inmsg;
	cout << msg;
	cin >> inmsg;
	return inmsg;
}

[mbozzi]

Do not place using directives in header files.
Because of how overload resolution works, there is a potential for using namespace declarations to at worst silently change the behavior of the program. By including that header file, you silently introduce a large number of common names which may silently collide with those in your code.

This has been a topic of active discussion on this forum before: see, e.g.,
http://www.cplusplus.com/forum/beginner/212153/#msg992333

Personally, I don't introduce namespace using declarations at global scope, especially not for namespace std. Where necessary, I introduce namespace aliases. In my opinion, this reduces ambiguity and results in clearer and less error-prone code.

Use const where applicable. Consider passing potentially expensive-to-copy objects (like std::string) by reference (const reference here).

int write(string const& msg) { ... }
int print(string const& msg) { ... } 
std::string input(std::string const& msg) { ... }

Otherwise, it looks good. Be aware that std::system("pause") requires the user to be sitting at the computer to un-pause it, which defeats the point of most command line programs, which should be designed to be used non-interactively.

[Handy Andy]

Hello Cyndanera,

Not much I could add to what mbozzi said,but for the "system("pause");" you can check this out:
http://www.cplusplus.com/forum/beginner/1988/

Something I do is:

#define DEBUG

#ifdef DEBUG
    code for pause
#endif 

This will use this code until you comment out the #define. This way you can have the pause when working with the program and by putting a comment on the "#define DEBUG" this code will not be included in the final compile, so the program will not pause at the end, but exit the window.

Hope that helps,

Andy