Made to order, just as we compile and run the Build menu and choose Run, or press F9 appears a window that displays the result of the operation of the code, that is, to display the words "Hello world!" debuted on the screen.
Executing your code that we compile and run by the Build and Run menu or press the F9 key window appears that displays the results of running code. Which is to display the word "Hello world!" To the screen.
The order of the code we have compiled works by menu choice and Build Run or hit F9 appears at the window to display the results of working code. Which is the word "Hello world!" out on the screen.