My program doesn't put characters out on the screen - c++

Question

I have tried several things but none of them did work. Does someone know what the problem is? Here's my code:
#include <iostream>
#include <Windows.h>
#include <iomanip>
#include <fstream>
#include <stdio.h>
using namespace std;
int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int CmdShow) {
cout << "Hello World" << endl;
return 0;
}
Thanks

Answer 1

If you are using visual studio, and create a Win32 application, it will not create a console so the output does not appear on any window. If you create a Win32 Console application, std::cout will be directed to the console window but you will need to use a standard main() program entry point.
To avoid creating a new project, modify your code as shown here:
int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int CmdShow) {
AllocConsole();
AttachConsole(GetCurrentProcessId());
freopen("CONOUT$", "w", stdout);
cout << "Hello World" << endl;
return 0;
}

Answer 2

On Windows, there are two main types of programs:
Console applications for single textual input and output. These are typically started from the command line in a command prompt.
GUI applications which use windows, buttons, the mouse, touch, etc. These are typically started by choosing from the start menu or double-clicking on an icon.
(There are ways to have a single application work both ways, but that's almost certainly not what you're after.)
Your code is exhibiting indications of trying to be both. It has a wWinMain, which suggests it's a GUI application, but it does regular textual output using std::cout, which suggests it's a console application.
I think you want a console application, but you accidentally started by choosing a Win32 application in the Visual Studio New Project Wizard. To fix this without starting over:
First, get rid of the unnecessary includes, specifically, delete #include <windows.h>.
Next Change the wWinMain to a standard C++ main function, like this:
int main() {
cout << "Hello World" << endl;
return 0;
}
Finally, right-click on your project in the Solution Explorer, and choose Properties from the pop-up menu. At the top of the pop-up dialog, set Configuration to All Configurations. In the left side, expand Linker and choose System, then, on the right side, change the SubSystem field to Console (/SUBSYSTEM:CONSOLE). Click OK.
Now you should be able to rebuild your program and it'll work.
One word of warning: If you run it directly from Visual Studio, a new console window will appear and, in the blink of an eye, your program will complete and the new console window will disappear, which makes it hard to tell if you did the right thing.
If you start your program from a CMD prompt, you won't have that problem. If you want to run from the debugger, put a breakpoint on the return statement in your main function. That will halt the program in the debugger just before it ends, and you'll be able to see what's in the console window. Some people have the program ask for keyboard input right before it finishes, which gives the user a change to see what's in the console window before it vanishes.

Answer 3

It appears you have created a windows application rather than a console application.
A console application has a main function with signature:
int main(int argc, char ** argv);
A windows application has a main function with signature:
int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int CmdShow);
The latter is intended for applications that actually create a window. You choose which to create using the wizard in Visual Studio when you go to create a new project (assuming you are using Visual Studio).
Use:
https://msdn.microsoft.com/en-us/library/ms235629.aspx
Also, it is possible your application is exiting before you see the output.
In this case, we can use a non-standard platform specific call to ::system("pause") to make it wait until you hit a key to continue.
#include <iostream>
#include <iomanip>
#include <fstream>
#include <windows.h>
using namespace std;
int main(int argc, char ** argv)
{
cout << "Hello World" << endl;
system("pause");
return 0;
}
Alternativly, place a break point on the line where it says return 0; and use F5 to debug.