Search with searchable modifier in iOS Swift - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ ui_behavior

intermediate

Searchable Modifier Filtering Behavior

Given this SwiftUI code snippet using the searchable modifier, what will be the displayed list items when the user types "ap" in the search bar?

iOS Swift

struct ContentView: View {
  @State private var searchText = ""
  let fruits = ["Apple", "Banana", "Grape", "Apricot", "Orange"]

  var filteredFruits: [String] {
    if searchText.isEmpty {
      return fruits
    } else {
      return fruits.filter { $0.localizedCaseInsensitiveContains(searchText) }
    }
  }

  var body: some View {
    List(filteredFruits, id: \.self) { fruit in
      Text(fruit)
    }
    .searchable(text: $searchText)
  }
}

A ["Grape", "Apricot"]

B ["Apple", "Banana", "Grape", "Apricot", "Orange"]

C ["Apple", "Apricot"]

D ["Banana", "Orange"]

💡 Hint

Think about how the filter uses localizedCaseInsensitiveContains with the search text.

The filter returns fruits that contain the substring "ap" ignoring case. "Apple" and "Apricot" both contain "ap" ignoring case, so only these two appear.

❓ lifecycle

intermediate

Search Text State Update Timing

In SwiftUI, when using the searchable modifier with a @State searchText variable, when does the searchText update as the user types?

A searchText updates only when the view reloads

B searchText updates only after the user presses Return

C searchText updates only when the search bar loses focus

D searchText updates immediately on every character typed

💡 Hint

Consider how SwiftUI binds the search bar text to the state variable.

The searchable modifier binds the search bar text to the @State variable, updating it immediately as the user types each character.

❓ navigation

advanced

Searchable Modifier with NavigationView

What is the correct way to add a searchable modifier to a list inside a NavigationView so that the search bar appears in the navigation bar on iOS?

iOS Swift

struct ContentView: View {
  @State private var searchText = ""
  let items = ["One", "Two", "Three"]

  var body: some View {
    NavigationView {
      List(items, id: \.self) { item in
        Text(item)
      }
      // Where to place searchable modifier?
    }
  }
}

A Place .searchable(text: $searchText) directly on the List inside NavigationView

B Place .searchable(text: $searchText) on the NavigationView itself

C Place .searchable(text: $searchText) outside NavigationView wrapping the whole view

D Place .searchable(text: $searchText) on the Text inside the List

💡 Hint

The searchable modifier must be attached to the view that produces the list content inside the navigation.

The searchable modifier should be applied to the List inside the NavigationView to show the search bar in the navigation bar area.

📝 Syntax

advanced

Correct Syntax for searchable Modifier with Prompt

Which option shows the correct syntax to add a searchable modifier with a prompt text "Search fruits" in SwiftUI?

A .searchable($searchText, placeholder: "Search fruits")

B .searchable(text: $searchText, prompt: "Search fruits")

C .searchable(text: searchText, prompt: "Search fruits")

D .searchable(text: $searchText, placeholder: "Search fruits")

💡 Hint

Check the parameter names and use of $ for binding.

The searchable modifier requires a binding to a String with $ and the prompt parameter is named prompt, not placeholder.

🔧 Debug

expert

Why Does Searchable Not Show Search Bar?

You added .searchable(text: $searchText) to your List inside a NavigationView, but the search bar does not appear on iOS 14. What is the reason?

A The searchable modifier is only available on iOS 15 and later

B You forgot to add a NavigationLink inside the List

C The searchText variable is not marked with @State

D The List must be wrapped in a VStack for searchable to work

💡 Hint

Check the iOS version compatibility of the searchable modifier.

The searchable modifier was introduced in iOS 15, so it does not work on iOS 14 or earlier versions.

Practice

1. What does the searchable modifier do in a SwiftUI view?

easy

A. Removes all items from the list when typing.

B. Automatically sorts the list items alphabetically.

C. Changes the background color of the list.

D. Adds a search bar to filter content in lists or scroll views.

Solution

1. Step 1: Understand the purpose of searchable

   The searchable modifier adds a search bar UI element to a list or scroll view.

2. Step 2: Identify its effect on content

   It allows users to type text to filter or search through the displayed content.

3. Final Answer:

   Adds a search bar to filter content in lists or scroll views. -> Option D

4. Quick Check:

   searchable = search bar added [OK]

Hint: searchable always adds a search bar UI [OK]

Common Mistakes:

• Thinking searchable sorts items automatically
• Confusing searchable with styling modifiers
• Assuming searchable removes items without filtering

2. Which of the following is the correct syntax to add a searchable modifier with a binding to a @State variable named searchText?

easy

A. .searchable(searchText)

B. .searchable($searchText)

C. .searchable(text: $searchText)

D. .searchable(text: searchText)

Solution

1. Step 1: Recall the searchable syntax

   The searchable modifier requires a binding to a string, written as text: $variable.

2. Step 2: Match the correct binding syntax

   Using $searchText passes the binding, so the correct syntax is .searchable(text: $searchText).

3. Final Answer:

   .searchable(text: $searchText) -> Option C

4. Quick Check:

   Binding uses $ with variable name [OK]

Hint: Use $ to bind @State variable in searchable [OK]

Common Mistakes:

• Omitting the text: label
• Not using $ for binding
• Passing variable without binding

3. Given this SwiftUI code snippet, what will be displayed when the user types "ap" in the search bar?

struct ContentView: View {
  @State private var searchText = ""
  let fruits = ["Apple", "Banana", "Grape", "Apricot"]

  var filteredFruits: [String] {
    if searchText.isEmpty { return fruits }
    return fruits.filter { $0.lowercased().contains(searchText.lowercased()) }
  }

  var body: some View {
    List(filteredFruits, id: \.self) { fruit in
      Text(fruit)
    }
    .searchable(text: $searchText)
  }
}

medium

A. ["Apple", "Apricot"]

B. ["Banana", "Grape"]

C. ["Apple", "Banana", "Grape", "Apricot"]

D. Empty list

Solution

1. Step 1: Understand filtering logic

   The filter checks if each fruit contains the search text "ap" ignoring case.

2. Step 2: Apply filter to fruits list

   "Apple" and "Apricot" contain "ap" (case-insensitive), "Banana" and "Grape" do not match exactly.

3. Final Answer:

   ["Apple", "Apricot"] -> Option A

4. Quick Check:

   Filter by contains "ap" = Apple, Apricot [OK]

Hint: Filter checks contains ignoring case [OK]

Common Mistakes:

• Including fruits that don't contain "ap"
• Ignoring case sensitivity
• Returning full list regardless of search

4. Identify the error in this SwiftUI code using searchable:

struct ContentView: View {
  @State var searchText = ""
  let items = ["One", "Two", "Three"]

  var filteredItems: [String] {
    items.filter { $0.contains(searchText) }
  }

  var body: some View {
    List(filteredItems, id: \.self) { item in
      Text(item)
    }
    .searchable(text: searchText)
  }
}

medium

A. Missing $ to bind searchText in searchable modifier.

B. filteredItems should be a @State variable.

C. List requires a ForEach instead of direct array.

D. searchText should be a constant, not @State.

Solution

1. Step 1: Check searchable binding syntax

   The searchable modifier requires a binding, so it must be text: $searchText, not text: searchText.

2. Step 2: Verify other code parts

   filteredItems is computed correctly, List accepts array with id, and searchText should be @State.

3. Final Answer:

   Missing $ to bind searchText in searchable modifier. -> Option A

4. Quick Check:

   Binding needs $ prefix [OK]

Hint: Always use $ for @State binding in searchable [OK]

Common Mistakes:

• Forgetting $ in searchable binding
• Making filteredItems @State unnecessarily
• Confusing List requirements

5. You want to create a searchable list of contacts where typing filters by first or last name. Which code snippet correctly implements this behavior?

struct Contact: Identifiable {
  let id = UUID()
  let firstName: String
  let lastName: String
}

struct ContentView: View {
  @State private var searchText = ""
  let contacts = [Contact(firstName: "John", lastName: "Doe"), Contact(firstName: "Jane", lastName: "Smith"), Contact(firstName: "Alice", lastName: "Johnson")]

  var filteredContacts: [Contact] {
    if searchText.isEmpty { return contacts }
    return contacts.filter { contact in
      contact.firstName.lowercased().contains(searchText.lowercased()) || contact.lastName.lowercased().contains(searchText.lowercased())
    }
  }

  var body: some View {
    List(filteredContacts) { contact in
      Text("\(contact.firstName) \(contact.lastName)")
    }
    .searchable(text: $searchText)
  }
}

hard

A. Filters contacts only by first name and ignores last name.

B. Filters contacts by first or last name ignoring case and updates list dynamically.

C. Filters contacts but does not ignore case, so search is case-sensitive.

D. Does not filter contacts and always shows full list.

Solution

1. Step 1: Analyze filtering logic

   The filter checks if either firstName or lastName contains the search text, ignoring case.

2. Step 2: Confirm UI updates with searchable

   The searchable modifier binds to $searchText, so typing updates the filteredContacts list dynamically.

3. Final Answer:

   Filters contacts by first or last name ignoring case and updates list dynamically. -> Option B

4. Quick Check:

   Filter by first or last name, case-insensitive [OK]

Hint: Filter with OR condition and ignore case for full search [OK]

Common Mistakes:

• Filtering only by first name
• Not using lowercased() causing case sensitivity
• Forgetting to bind searchText with $