NavigationStack in iOS Swift - Mini App: Build & Ship

Build: Simple NavigationStack Example

This screen shows a list of items. When you tap an item, it navigates to a detail screen showing the item's name.

Target UI

---------------------
| Simple Navigation |
|-------------------|
| > Item 1          |
| > Item 2          |
| > Item 3          |
|                   |
---------------------

Use NavigationStack as the root navigation container

Show a list of three items labeled 'Item 1', 'Item 2', and 'Item 3'

When an item is tapped, navigate to a detail screen

Detail screen shows the tapped item's name in large text

Add a back button to return to the list

Starter Code

iOS Swift

import SwiftUI

struct ContentView: View {
    var body: some View {
        // TODO: Add NavigationStack and list here
        Text("Hello, World!")
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

Task 1

Task 2

Task 3

Solution

iOS Swift

import SwiftUI

struct ContentView: View {
    let items = ["Item 1", "Item 2", "Item 3"]

    var body: some View {
        NavigationStack {
            List(items, id: \.self) { item in
                NavigationLink(value: item) {
                    Text(item)
                }
            }
            .navigationTitle("Simple Navigation")
            .navigationDestination(for: String.self) { item in
                DetailView(itemName: item)
            }
        }
    }
}

struct DetailView: View {
    let itemName: String

    var body: some View {
        Text(itemName)
            .font(.largeTitle)
            .navigationTitle(itemName)
            .navigationBarTitleDisplayMode(.inline)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

We use NavigationStack as the root container to manage navigation. Inside it, a List shows three items. Each item is a NavigationLink that, when tapped, pushes a DetailView onto the stack. The detail view displays the selected item's name in large text and sets the navigation bar title. The back button is automatically provided by NavigationStack to return to the list.

Final Result

Completed Screen

---------------------
| Simple Navigation |
|-------------------|
| > Item 1          |
| > Item 2          |
| > Item 3          |
|                   |
---------------------

-- After tapping 'Item 2' --
---------------------
| Item 2            |
|-------------------|
|                   |
|     Item 2        |
|                   |
|                   |
---------------------

Tap on any item in the list to navigate to the detail screen showing that item's name

Use the back button in the navigation bar to return to the list

Stretch Goal

Add a button on the list screen that navigates to a new screen showing a welcome message.

💡 Hint

Add a toolbar button inside NavigationStack using .toolbar modifier with a NavigationLink to a new view.

Practice

1. What is the main purpose of NavigationStack in SwiftUI?

easy

A. To organize screens in a stack for easy navigation

B. To create animations for buttons

C. To manage data storage locally

D. To handle network requests

Solution

1. Step 1: Understand NavigationStack role

   NavigationStack is designed to manage a stack of views for navigation.

2. Step 2: Compare with other options

   Options A, B, and C relate to networking, animations, and data storage, which are unrelated to navigation stacks.

3. Final Answer:

   To organize screens in a stack for easy navigation -> Option A

4. Quick Check:

   NavigationStack = Screen stack for navigation [OK]

Hint: NavigationStack stacks screens for navigation [OK]

Common Mistakes:

• Confusing NavigationStack with animation or data management
• Thinking NavigationStack handles network calls
• Assuming NavigationStack is for UI styling only

2. Which of the following is the correct syntax to create a navigation link inside a NavigationStack in SwiftUI?

easy

A. NavigationLink(destination: DetailView()) { Text("Go") }

B. NavigationLink { Text("Go") } destination: DetailView()

C. NavigationLink(Text("Go"), DetailView())

D. NavigationLink(destination: "DetailView") { Text("Go") }

Solution

1. Step 1: Recall NavigationLink syntax

   The correct syntax uses NavigationLink(destination: View) { Label }.

2. Step 2: Check each option

   NavigationLink(destination: DetailView()) { Text("Go") } matches the correct syntax. NavigationLink { Text("Go") } destination: DetailView() reverses parameters incorrectly. NavigationLink(Text("Go"), DetailView()) uses wrong parameter order. NavigationLink(destination: "DetailView") { Text("Go") } passes destination as a string, which is invalid.

3. Final Answer:

   NavigationLink(destination: DetailView()) { Text("Go") } -> Option A

4. Quick Check:

   NavigationLink syntax = destination first, label second [OK]

Hint: Destination view goes first, label closure second [OK]

Common Mistakes:

• Swapping destination and label parameters
• Passing destination as a string instead of a view
• Using incorrect parentheses or braces

3. Given this SwiftUI code inside a NavigationStack:

NavigationLink(destination: Text("Detail Screen")) {
  Text("Tap me")
}

What happens when the user taps "Tap me"?

medium

A. Nothing happens because NavigationLink is missing a tag

B. The app navigates to a screen showing "Detail Screen" text

C. The app crashes due to missing navigation title

D. The button changes color but does not navigate

Solution

1. Step 1: Understand NavigationLink behavior

   Tapping the link navigates to the destination view, here a Text view with "Detail Screen".

2. Step 2: Verify other options

   Nothing happens because NavigationLink is missing a tag is incorrect; tags are optional. The app crashes due to missing navigation title is wrong; navigation title is not required to navigate. The button changes color but does not navigate describes visual feedback only, not navigation.

3. Final Answer:

   The app navigates to a screen showing "Detail Screen" text -> Option B

4. Quick Check:

   NavigationLink tap = navigate to destination [OK]

Hint: Tap NavigationLink to go to its destination view [OK]

Common Mistakes:

• Thinking NavigationLink needs a tag to work
• Assuming navigation title is mandatory for navigation
• Confusing visual feedback with navigation action

4. What is wrong with this SwiftUI code snippet inside a NavigationStack?

NavigationLink(destination: DetailView) {
  Text("Next")
}

medium

A. NavigationLink cannot be used inside NavigationStack

B. Text("Next") should be outside the NavigationLink

C. DetailView is missing parentheses to create an instance

D. The destination must be a string, not a view

Solution

1. Step 1: Check destination parameter

   Destination expects a view instance, so DetailView() is required, not just DetailView.

2. Step 2: Validate other options

   Text("Next") should be outside the NavigationLink is wrong; Text is correctly inside NavigationLink. NavigationLink cannot be used inside NavigationStack is false; NavigationLink is designed for NavigationStack. The destination must be a string, not a view is incorrect; destination must be a view, not a string.

3. Final Answer:

   DetailView is missing parentheses to create an instance -> Option C

4. Quick Check:

   Destination needs view instance with () [OK]

Hint: Destination must be a view instance with parentheses [OK]

Common Mistakes:

• Passing view type instead of instance as destination
• Placing label outside NavigationLink
• Confusing destination type with string

5. You want to create a NavigationStack with a list of items. Tapping an item should navigate to a detail view showing the item's name. Which code snippet correctly implements this behavior?

hard

A. NavigationStack {
List(items, id: \.self) { item in
NavigationLink(destination: item) {
Text(item)
}
}
}

B. NavigationStack {
ForEach(items) { item in
NavigationLink(Text(item), destination: Text(item))
}
}

C. NavigationStack {
List(items) { item in
Button(action: { navigateTo(Text(item)) }) {
Text(item)
}
}
}

D. NavigationStack {
List(items, id: \.self) { item in
NavigationLink(destination: Text(item)) {
Text(item)
}
}
}

Solution

1. Step 1: Check List and NavigationLink usage

   NavigationStack { List(items, id: \.self) { item in NavigationLink(destination: Text(item)) { Text(item) } } } correctly uses List with id, and NavigationLink with destination as a Text view showing the item.

2. Step 2: Analyze other options

   NavigationStack { ForEach(items) { item in NavigationLink(Text(item), destination: Text(item)) } } uses incorrect NavigationLink syntax. NavigationStack { List(items) { item in Button(action: { navigateTo(Text(item)) }) { Text(item) } } } uses Button with undefined navigateTo function, which is invalid. NavigationStack { List(items, id: \.self) { item in NavigationLink(destination: item) { Text(item) } } } passes item (a String) directly as destination, which is invalid; destination must be a view.

3. Final Answer:

   NavigationStack with List and NavigationLink using destination: Text(item) -> Option D

4. Quick Check:

   List + NavigationLink with view destination = correct [OK]

Hint: Use NavigationLink with destination view inside List [OK]

Common Mistakes:

• Passing data instead of view as destination
• Using Button instead of NavigationLink for navigation
• Incorrect NavigationLink parameter order