CoreDataで作るTableView

testCoreData.swift

import UIKit
import CoreData

class ViewController: UIViewController,UITextFieldDelegate {
    
    @IBOutlet weak var textField: UITextField!
    @IBOutlet weak var tableView: UITableView!
     
    var monsters:[Monster] = []  
    var manager = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        textField.delegate = self   
        let getData = NSFetchRequest<NSFetchRequestResult>(entityName: "Monster")
        do{
            monsters = try manager.fetch(getData) as! [Monster]
        }catch{
            print("エラーだよ")
        }  
    }
    
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()       
        let newObj = Monster(context: self.manager)
        newObj.name = textField.text
        self.monsters.append(newObj)
        (UIApplication.shared.delegate as! AppDelegate).saveContext()      
        tableView.reloadData()
        textField.text = ""
        return true
    }
}

extension ViewController: UITableViewDataSource{
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return monsters.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell:UITableViewCell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
        let monData = monsters[indexPath.row]
        cell.textLabel?.text = monData.name
        return cell
    }
  
}