Xcode gives me an error when I try to add a new view controller

I'm new to Objective-C and am currently following a tutorial in a book that is showing me how to add a new view and view controller to an existing window.

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The book at this point tells me:

"Add a TestViewController instance to your code and label it as an IBOutlet. We are putting it in the app delegate class, TestAppDelegate. In TestAppDeligate.h the new code will look like this:

IBOutlet TestViewController* testViewController; "

So when I alter my app delegate header-file to include this line of code it looks like this.

 #import <UIKit/UIKit.h>
 #import "TestViewController.h"

 @class views_and_controllersViewController;

 @interface views_and_controllersAppDelegate : NSObject
 <UIApplicationDelegate> {

 }

 @property (nonatomic, retain) IBOutlet UIWindow *window;

 @property (nonatomic, retain) IBOutlet
 views_and_controllersViewController *viewController;

 IBOutlet TestViewController* testViewController;

 @end

However at this point Xcode throws me the error:

Cannot declare variable inside @interface or @protocol

as well as the warning:

iboutlet attribute can only be applied to instance variables or properties

I haven't failed to notice that all other instance declarations in the header file are prefixed with the @property tag. Is this required? And if so has the book simply omitted this with the expectation that I already knew that Obj-C expects this?

Anywho, what am I doing wrong here?

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Your IBOutlet TestViewController *testViewController needs to be moved up inside the @interface section.