Why lists present dynamic content in iOS Swift - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a SwiftUI List that shows items from an array.

iOS Swift

List([1]) { item in
    Text(item)
}

Drag options to blanks, or click blank then click option'

AVStack

BText

Citems

DButton

Attempts:

3 left

💡 Hint

Common Mistakes

Using UI elements like Text or Button instead of the data array.

Leaving the List empty without data.

The List needs a data source array to show dynamic content. Here, items is the array.

2fill in blank

medium

Complete the code to make the List update when the data changes.

iOS Swift

@State private var fruits = ["Apple", "Banana", "Cherry"]

var body: some View {
    List([1]) { fruit in
        Text(fruit)
    }
}

Drag options to blanks, or click blank then click option'

Afruits

Bself.fruits

C@fruits

Dvar fruits

Attempts:

3 left

💡 Hint

Common Mistakes

Adding self. inside the List parameter causes errors.

Using @fruits is invalid syntax here.

The List uses the @State variable fruits to show dynamic content that updates automatically.

3fill in blank

hard

Fix the error in the List code by completing the blank with the correct identifier for unique items.

iOS Swift

List(fruits, id: [1]) { fruit in
    Text(fruit)
}

Drag options to blanks, or click blank then click option'

Aself

Bid

Cfruit

D\.self

Attempts:

3 left

💡 Hint

Common Mistakes

Using id or self without the backslash causes errors.

Using fruit is invalid here.

Using id: \.self tells SwiftUI to use the item itself as a unique identifier, which is needed for simple types like String.

4fill in blank

hard

Fill both blanks to create a List that shows numbers from 1 to 5 with their squares.

iOS Swift

let numbers = Array(1...5)

List(numbers, id: [1]) { num in
    Text("\(num) squared is \(num [2] num)")
}

Drag options to blanks, or click blank then click option'

A\.self

B*

C+

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of * changes the meaning.

Using num as id without backslash causes errors.

The List uses \.self as id for unique numbers. The square is calculated by multiplying num * num.

5fill in blank

hard

Fill all three blanks to create a dynamic List showing names and ages from a dictionary.

iOS Swift

let people = ["Alice": 30, "Bob": 25, "Carol": 27]

List(people.keys.sorted(), id: [1]) { name in
    Text(name)
    Text("Age: \(people[[2]] ?? 0)")
    Text("Name length: \([3].count)")
}

Drag options to blanks, or click blank then click option'

A\.self

Bname

Dpeople

Attempts:

3 left

💡 Hint

Common Mistakes

Using people as id causes errors.

Using wrong variable names inside the Text views.

The List uses \.self as id for unique names. The age is accessed by people[name]. The length of the name is name.count.