Structs vs classes in iOS Swift - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a struct named Person with a name property.

iOS Swift

struct Person {
  var [1]: String
}

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

Aname

Bage

Cheight

Dweight

Attempts:

3 left

💡 Hint

Common Mistakes

Using unrelated property names like age or height.

The property to store the person's name should be called name.

2fill in blank

medium

Complete the code to create an instance of the Person struct named person1.

iOS Swift

let person1 = [1](name: "Alice")

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Astruct

Bclass

CPerson

Dvar

Attempts:

3 left

💡 Hint

Common Mistakes

Using keywords like class or var instead of the struct name.

To create an instance of a struct, use its name Person followed by parentheses.

3fill in blank

hard

Fix the error in the code by choosing the correct keyword to define a class named Animal.

iOS Swift

[1] Animal {
  var species: String
}

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Aclass

Bfunc

Cstruct

Dlet

Attempts:

3 left

💡 Hint

Common Mistakes

Using struct or func instead of class.

Classes are defined using the keyword class in Swift.

4fill in blank

hard

Fill both blanks to complete the code that shows how classes support inheritance but structs do not.

iOS Swift

class Dog: [1] {
  var breed: String
  init(breed: String) {
    self.breed = breed
  }
}

struct [2] {
  var color: String
}

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

AAnimal

BPerson

CCar

DDog

Attempts:

3 left

💡 Hint

Common Mistakes

Using struct names that imply inheritance or using wrong base class names.

The class Dog inherits from the class Animal. Structs like Car cannot inherit.

5fill in blank

hard

Fill all three blanks to complete the code that demonstrates value type behavior of structs and reference type behavior of classes.

iOS Swift

struct Point {
  var x: Int
  var y: Int
}

var p1 = Point(x: 0, y: 0)
var p2 = p1
p2.x = [1]

class Location {
  var name: String
  init(name: String) {
    self.name = name
  }
}

var loc1 = Location(name: "Home")
var loc2 = loc1
loc2.name = [2]

print(p1.x) // [3]

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A10

B"Work"

C0

D"Home"

Attempts:

3 left

💡 Hint

Common Mistakes

Thinking structs behave like classes and share references.

Changing p2.x does not affect p1.x because structs are value types. So p1.x remains 0. Changing loc2.name changes loc1.name because classes are reference types.