class SwiftCoreDataHelper {

    //Get saved data
    func getData(forEntity: String, andSaveToArray entityArray: inout [NSManagedObject]) {

        //Get managedContext, refrence to AppDelegate, and prepare fetchRequest
        guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {return}
        let managedContext = appDelegate.persistentContainer.viewContext
        let fetchRequest = NSFetchRequest<NSManagedObject>(entityName: "(forEntity)")

        //Get saved data
        do {
            entityArray = try managedContext.fetch(fetchRequest)
        } catch let error as NSError {
            print("Could not fetch. (error), (error.userInfo)")
        }
    }

    //Save data
    func save(name: String, useEntity nameOfEntity: String, useArray entityArray: inout [NSManagedObject], usingKeypathName appropriateKeyPathName: String) {

        guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {return}
        let managedContext = appDelegate.persistentContainer.viewContext
        let entity = NSEntityDescription.entity(forEntityName: nameOfEntity, in: managedContext)!
        let genericItem = NSManagedObject(entity: entity, insertInto: managedContext)
        genericItem.setValue(name, forKeyPath: appropriateKeyPathName)

        do { //Save context and add to array
            try managedContext.save()
            entityArray.append(genericItem)
        } catch let error as NSError {
            print("Could not save. (error), (error.userInfo)")
        }
    }

    //Updating stored data
    func updateData(forEntity: String, updateValueTo updatedValue: String, andSaveToArray entityArray: inout [NSManagedObject]){

        //Get managedContext, refrence to AppDelegate, and prepare fetchRequest
        guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {return}
        let managedContext = appDelegate.persistentContainer.viewContext
        let fetchRequest = NSFetchRequest<NSManagedObject>(entityName: "(forEntity)")

        do {
            let fetched = try managedContext.fetch(fetchRequest)
            let objectUpdate = fetched.last! as! NSManagedObject

            //Update value
            objectUpdate.setValue(updatedValue, forKey: "name")

            do { //Save context
                try managedContext.save()
            }
            catch {
                print(error)
            }
        }
        catch {
            print(error)
        }
    }

    //Delete saved data
    func deleteData(forEntity: String){

        //Get managedContext, refrence to AppDelegate, and prepare fetchRequest
        guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {return}
        let managedContext = appDelegate.persistentContainer.viewContext
        let fetchRequest = NSFetchRequest<NSManagedObject>(entityName: "(forEntity)")

        do {
            let fetched = try managedContext.fetch(fetchRequest)

            //Delete object
            let objectToDelete = fetched as! [NSManagedObject]
            if (objectToDelete.count != 0){ //Do not delete if nothing to delete
                managedContext.delete(objectToDelete.last!)
            }

            do { //Save context
                try managedContext.save()
            }
            catch {
                print(error)
            }
        }
        catch {
            print(error)
        }
      }
    }

let myData = SwiftCoreDataHelper()
var people: [NSManagedObject] = []

//Write data to entity previously created in xcdatamodeld file
let personName = "Harry"
myData.save(name: personName, useEntity: "Person", useArray: &people, usingKeypathName: "name")

//Fetch data saved in an Entity:
myData.getData(forEntity: "Person", andSaveToArray: &people)
Update data in an entity as follows

//Update data in an Entity
let otherName = "Tom"
myData.updateData(forEntity: "Person", updateValueTo: otherName, andSaveToArray: &people)
Remove an entity entirely as follows

//Delete all data in an Entity
myData.deleteData(forEntity: "Person")