How to switch between output window and code editor in Xcode
It is a little unclear what you really mean:

The Output pane is called the Console. It is displayed in the Debug area.

There are a few ways to get to it.

In the Toolbar Menu:

Use the Debug area toggle button. 



From the Menu Bar : View Menu :-> Debug area :-> Show the Debug area menu
to open the Debug area set as it was last displayed







Note the shortcut for this:  cmd +  shift +   Y

Use View Menu :-> Debug area :-> Activate Console area to Show the Debug area with the Console showing.









Note the shortcut for this:  cmd +  shift +   C

Or just show the Console area if the debug area is already showing.

You can also use the Debug area show hide toggle to show/hide either the Variable View or the  Console area  view