This is my first time to implement In-App purchase and I am using the tutorial located here: Ray Wenderlich

Now I am sure this is something simple, but I am having issues figuring out, so I figured I would ask all of the gurus out here.

The compiler is saying that _products is Use of undeclared identifier

 - (void)productPurchased:(NSNotification *)notification {

 NSString * productIdentifier = notification.object;
 [_products enumerateObjectsUsingBlock:^(SKProduct * product, NSUInteger idx, BOOL *stop) {
 if ([product.productIdentifier isEqualToString:productIdentifier]) {



 *stop = YES;
 }
 }];

 }