core data - managedObjectContext in Swift 3 -

i want work through this example code in swift , coredata used create table. however, using swift 3 fail work. importantly, cannot replace line

// set nsmanagedobjectcontext   let appdelegate = nsapplication.sharedapplication().delegate as! appdelegate   managedcontext = appdelegate.managedobjectcontext 

even though found this related question (which ios not os x). how can replace piece of code produces error message value of type 'appdelegate' has no member 'managedcontext'?

swift 3 in macos

let appdelegate = nsapplication.shared().delegate as! appdelegate let managedcontext = appdelegate.managedobjectcontext 

the error provided says 'appdelegate' has no member 'managedcontext' instead of 'appdelegate' has no member 'managedobjectcontext', lead me assume need fix syntax.

swift 3 in ios 10

core data needs @ least 3 things work:

1. a managed object model
2. a persistent store coordinator
3. and managed object context

put 3 things , core data stack.

when ios 10 came out, new object introduced called nspersistentcontainer encapsulates core data stack.

how create container object answered here.

managedobjectcontext property called viewcontext, accessed via:

let delegate = uiapplication.shared.delegate as! appdelegate let managedobjectcontext = delegate.persistentcontainer.viewcontext 

a helpful article what's new in core data, if reading seems little heavy, wwdc video great job of explaining topic.