When you hit Build and Run button in Xcode the application will start.

If everything is ok you should see messages from the application displayed in the lower right part of Xcode window. The Console output contains text printed by the application.

Sometimes it might happen that there is no Console output window. How to fix it?

Here is small tip for Xcode developers.

To show/hide the Console click the icon Show/Hide the console in the lower right corner. It’s the last icon on the lower right side of the panel.