Creating a fully functional to‑do list iPhone app from scratch is a complex process that involves several steps and requires knowledge of several programming languages and tools. Here is a high‑level overview of the steps involved:

1. Choose a development platform: For developing an iPhone app, you need to use Apple's development platform Xcode, which is available for free from the App Store. Xcode is an integrated development environment (IDE) that provides all the necessary tools for building and testing iOS apps.

2. Create a new Xcode project: Open Xcode and create a new project by selecting "File" > "New" > "Project" from the main menu. Choose the "App" option, select "iOS" as the platform, and choose "Single View App" as the template.

3. Set up the project: Name your project and set the language to Swift. Select a location to save your project, and click "Create."

4. Design the user interface: Xcode provides a drag-and-drop interface builder that you can use to design your app's user interface. To add a new UI element, such as a button or a text field, drag it from the Object Library and drop it onto the design canvas.

5. Implement the functionality: Once you have designed the user interface, you need to implement the functionality of your to-do list app. Start by creating a data model to store the tasks, including the task name, due date, priority, and category. You can use the Swift programming language to define your data model.

6. Create a task list: Next, create a table view controller that displays the task list. The table view should display each task as a separate row and should include buttons for marking tasks as complete, editing tasks, and deleting tasks.

7. Add functionality to the task list: Implement the functions for adding a new task, marking a task as complete, editing a task, and deleting a task. Use the UITableViewDataSource and UITableViewDelegate protocols to handle the data source and delegate methods for the table view.

8. Add reminders: Add the ability for users to set reminders for their tasks. You can use the UNUserNotificationCenter framework to create and manage reminders.

9. Categorize tasks: Add the ability for users to categorize tasks by creating a new screen that allows users to select a category for each task. You can use the UIPickerView control to create a list of categories.

10. Prioritize tasks: Add the ability for users to prioritize tasks by allowing them to assign a priority level to each task. You can use UISegmentedControl to create a list of priority levels.

11. Test the app: Test the app thoroughly to ensure that it works as intended. Use the Simulator in Xcode to test the app on different iOS devices.

12. Publish the app: Once you are satisfied with the app, publish it to the App Store so that other users can download and use it.

Please note that this is only a high-level overview of the process, and each step may require a detailed explanation and additional code. You may need to follow detailed tutorials or seek guidance from experienced developers to build a fully functional to-do list iPhone app from scratch.

struct Task {
    var name: String
    var dueDate: Date?
    var priority: Int
    var category: String
}

import UIKit
class ViewController: UIViewController, UITableViewDelegate {
    var tasks = Task
    var recentlyDeletedTasks = Task
    weak var textField: UITextField!
    var tableView: UITableView!
    override func viewDidLoad() {
        super.viewDidLoad()
        setupViews()
    }
    private func setupViews() {
        let addButton = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTask(:)))
        navigationItem.rightBarButtonItem = addButton
        let tableView = UITableView()
        tableView.translatesAutoresizingMaskIntoConstraints = false
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "TaskCell")
        tableView.delegate = self
        tableView.dataSource = self
        view.addSubview(tableView)
        NSLayoutConstraint.activate([
            tableView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            tableView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
            tableView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
            tableView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor)
        ])
    }
func addTask( sender: Any) {
        // Create a new task with the data from the text field
        let task = Task(name: textField.text!, dueDate: nil, priority: 1, category: "Uncategorized")
        // Add the task to the array
        tasks.append(task)
        // Clear the text field
        textField.text = ""
        // Dismiss the keyboard
        textField.resignFirstResponder()
        // Reload the table view to display the new task
        tableView.reloadData()
    }
}
extension ViewController: UITableViewDataSource {
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "TaskCell", for: indexPath)
        if indexPath.section == 0 {
            let task = tasks[indexPath.row]
            cell.textLabel?.text = task.name
        } else if indexPath.section == 1 {
            let task = recentlyDeletedTasks[indexPath.row]
            cell.textLabel?.text = task.name
            cell.textLabel?.textColor = .red // Change the text color to red to indicate recently deleted task
        }
        return cell
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if section == 0 {
            // Return the number of tasks in the array
            return tasks.count
        } else if section == 1 {
            // Return the number of recently deleted tasks
            return recentlyDeletedTasks.count
        }
        return 0
    }
    func numberOfSections(in tableView: UITableView) -> Int {
        return 2
    }
    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            // Remove the task from the array
            let deletedTask = tasks[indexPath.row]
            tasks.remove(at: indexPath.row)
            recentlyDeletedTasks.append(deletedTask)
            // Delete the row from the table view
            tableView.deleteRows(at: [indexPath], with: .fade)
        }
    }
}
extension ViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
    }
}
extension ViewController: UITextFieldDelegate {
    func textFieldShouldReturn(_ textField:

if !recentlyDeletedItems.isEmpty {
  Text("Recently Deleted")
    .font(.headline)
    .padding(.horizontal)
  List {
    ForEach(recentlyDeletedItems, id: .id) { item in
    HStack {
      Toggle(isOn: Binding(get: { 
      self.selectedItems.contains(recentlyDeletedItems.firstIndex(of: item)!)
    }, set: { newValue in
  let index = recentlyDeletedItems.firstIndex(of: item)!
  if newValue {
    self.selectedItems.insert(index)
              } else {
  self.selectedItems.remove(index)
         }
  recentlyDeletedItems[index].isIncluded = newValue
          })) {
  Text(item.title)
              }
          }
    }
  }
  .listStyle(.insetGrouped)
  .padding(.horizontal)
}
with the following code:
HStack {
  Text("Recently Deleted")
  .font(.headline)
  .padding(.horizontal)
  Spacer()
  Button(action: {
  self.showingRecentlyDeleted.toggle()
    }) {
        Image(systemName: showingRecentlyDeleted ? "chevron.up" : "chevron.down")
        .foregroundColor(.blue)
       }
}
if showingRecentlyDeleted {
  List {
    ForEach(recentlyDeletedItems, id: .id) { item in
    HStack {
      Toggle(isOn: Binding(get: {
        self.selectedItems.contains(recentlyDeletedItems.firstIndex(of: item)!)
          }, set: { newValue in
      let index = recentlyDeletedItems.firstIndex(of: item)!
      if newValue {
        self.selectedItems.insert(index)
      } else {
     self.selectedItems.remove(index)
        }
    recentlyDeletedItems[index].isIncluded = newValue
      })) {
          Text(item.title)
          }
      }
    }
  }
.listStyle(.insetGrouped)
.padding(.horizontal)
}

import UIKit
class ViewController: UIViewController {
    var tasks = Task
    weak var textField: UITextField!
    override func viewDidLoad() {
        super.viewDidLoad()
        setupViews()
    }
    private func setupViews() {
        let addButton = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTask(:)))
        navigationItem.rightBarButtonItem = addButton
        let tableView = UITableView()
        tableView.translatesAutoresizingMaskIntoConstraints = false
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "TaskCell")
        tableView.delegate = self
        tableView.dataSource = self
        view.addSubview(tableView)
        NSLayoutConstraint.activate([
            tableView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            tableView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
            tableView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
            tableView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor)
        ])
    }
func addTask( sender: Any) {
        // Create a new task with the data from the text field
        let task = Task(name: textField.text!, dueDate: nil, priority: 1, category: "Uncategorized")
        // Add the task to the array
        tasks.append(task)
        // Clear the text field
        textField.text = ""
        // Dismiss the keyboard
        textField.resignFirstResponder()
        // Reload the table view to display the new task
        tableView.reloadData()
    }
}
extension ViewController: UITableViewDataSource {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // Return the number of tasks in the array
        return tasks.count
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        // Dequeue a reusable cell from the table view
        let cell = tableView.dequeueReusableCell(withIdentifier: "TaskCell", for: indexPath)
        // Get the task for this row
        let task = tasks[indexPath.row]
        // Configure the cell with the task data
        cell.textLabel?.text = task.name
        return cell
    }
    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            // Remove the task from the array
            tasks.remove(at: indexPath.row)
            // Delete the row from the table view
            tableView.deleteRows(at: [indexPath], with: .fade)
        }
    }
}
extension ViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
    
}

This code defines a SwiftUI view for a todo list app. It includes a list of todo items, a way to add new items, and the ability to delete items and move them to a "Recently Deleted" section. The user can also select multiple items at once and perform actions on them, such as deleting or restoring them.

The TodoItem struct defines the properties of a todo item, including a unique identifier, a title, a boolean value indicating whether the item is completed, and a boolean value indicating whether the item is included in the list of recently deleted items.

The view includes several state variables, including selectedItems (a set of indices of selected items), showingRecentlyDeleted (a boolean indicating whether the "Recently Deleted" section is currently shown), newItemTitle (a string representing the title of a new item being added), isOn (a boolean representing the state of a switch control), todoItems (an array of TodoItem objects representing the current list of todo items), recentlyDeletedItems (an array of TodoItem objects representing the list of recently deleted items), and showingDeleteAlert (a boolean indicating whether the user has requested to delete an item).

The view includes a List view that displays the current list of todo items, with each item represented by a HStack containing a checkbox, the item title, and a trash can icon. The user can tap the checkbox to mark an item as completed, tap the title to select an item, and tap the trash can icon to delete an item.

The view also includes a HStack containing a text field and a button to add a new todo item to the list.

Finally, the view includes a section for recently deleted items that can be expanded or collapsed by tapping a chevron icon. Each recently deleted item is represented by a HStack containing a checkbox, the item title, and a button to restore the item. The user can select multiple items by tapping the checkboxes and can restore them all at once by tapping a "Return Selected Items" button.