This class is not key value coding-compliant

Cocoa Programming for OS X (5th Edition) 8. KVC, KVO, and Bindings
1

My environment is as follows: macOS Catalina Xcode 12 StoryBoard Single Window/View Controller - the view controller has custom code to populate a tableView in the View Controller The tableView has 7 columns and is populated from a SQLite table. The tableView displays data for 6 of the 7 columns. On the last column I get the following error: valueForUndefinedKey:]: this class is not key value coding-compliant for the key itemUsedLast.

I have searched for information on this error and what I have found is it seems to be saying that for the field itemUsedLast can not find an outlet? But in the case for a tableview the only IBOutlet is one for the entire tableView. Also, the identifiers in the storyboard match the code in the custom view controller.

I have completed several tableViews before and have not run into this issue.

I have tried several remedies but none resolved this issue.

Any thoughts on how to debug this further or resolve this will be appreciated.

Thanks

2

If you haven’t already done so, reading the following guides are worth the effort:

3

This is resolved. The problem was a mis-match in the names in NSObject, field identifiers and IB.

So as an example.

class Item: NSObject {
    @objc   var itemNumber: String? = ""
    @objc   var itemLastused: Date?
}

var items:[Item] = []
let item = Item()
item.itemNumber = "100"
item.itemLastused = Date()
items.append(item)
let valueForNumberKey = items[0].value(forKey: "itemNumber")
let valueForDateKey = items[0].value(forKey: "itemLastused

Besides the names matching here they also need to match in the IB.