Classes are reference types in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new instance of the class.

Swift

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

let myDog = [1](name: "Buddy")

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

ADog()

BDog

Cdog

Dclass Dog

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'dog' instead of 'Dog'.

Adding parentheses after the class name when not needed.

To create a new instance of a class, use the class name followed by parentheses with any required parameters.

2fill in blank

medium

Complete the code to change the name property of the Dog instance.

Swift

let myDog = Dog(name: "Buddy")
myDog.[1] = "Max"

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Aname

BName()

CsetName

DName

Attempts:

3 left

💡 Hint

Common Mistakes

Using uppercase 'Name' instead of lowercase 'name'.

Trying to call a method 'setName' which does not exist.

Properties are accessed using their exact name with correct case. Here, 'name' is the property to change.

3fill in blank

hard

Fix the error in the code to make both variables refer to the same Dog instance.

Swift

let dog1 = Dog(name: "Buddy")
let dog2 = [1]
dog2.name = "Charlie"
print(dog1.name)

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Adog1

BDog(name: "Charlie")

CDog()

Ddog2

Attempts:

3 left

💡 Hint

Common Mistakes

Creating a new Dog instance instead of assigning dog1.

Assigning dog2 to itself before initialization.

Assigning dog2 = dog1 makes both variables point to the same instance, so changes to dog2 affect dog1.

4fill in blank

hard

Fill both blanks to complete the class method that changes the dog's name.

Swift

class Dog {
    var name: String
    init(name: String) {
        self.name = name
    }
    func [1](newName: String) {
        self.[2] = newName
    }
}

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

AchangeName

Bname

CupdateName

DnewName

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'newName' as the property name instead of 'name'.

Using a method name that is not descriptive.

The method name can be 'changeName', and inside it, we assign the newName to the property 'name'.

5fill in blank

hard

Fill all three blanks to create a copy of a Dog instance and change the copy's name without affecting the original.

Swift

class Dog {
    var name: String
    init(name: String) {
        self.name = name
    }
    func copy() -> Dog {
        return Dog(name: self.[1])
    }
}

let dog1 = Dog(name: "Buddy")
let dog2 = dog1.[2]()
dog2.[3] = "Max"
print(dog1.name)

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

Aname

Bcopy

DchangeName

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning dog2 = dog1 instead of copying.

Changing dog2's name property incorrectly.

The copy method returns a new Dog with the same name. Calling dog1.copy() creates a new instance. Changing dog2.name does not affect dog1.