Computed properties in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a computed property that returns the double of the stored property.

Swift

struct Number {
    var value: Int
    var doubleValue: Int {
        return value [1] 2
    }
}

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

A/

B+

C-

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of * will add 2 instead of doubling.

Using / will divide instead of multiply.

The computed property doubleValue returns value multiplied by 2 using the * operator.

2fill in blank

medium

Complete the code to create a computed property that returns the full name by combining first and last names.

Swift

struct Person {
    var firstName: String
    var lastName: String
    var fullName: String {
        return firstName [1] " " [1] lastName
    }
}

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

A*

B+

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using * or - operators with strings causes errors.

Forgetting to add a space between names.

The computed property fullName concatenates firstName, a space, and lastName using the + operator.

3fill in blank

hard

Fix the error in the computed property to correctly calculate the area of a rectangle.

Swift

struct Rectangle {
    var width: Double
    var height: Double
    var area: Double {
        return width [1] height
    }
}

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

A+

B-

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using + adds dimensions instead of calculating area.

Using / or - gives wrong results.

The area of a rectangle is width multiplied by height, so the * operator is correct.

4fill in blank

hard

Fill both blanks to create a computed property that returns true if the number is even.

Swift

struct NumberChecker {
    var number: Int
    var isEven: Bool {
        return number [1] 2 [2] 0
    }
}

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

A%

B==

C!=

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using / instead of % to get remainder.

Using != instead of == causes wrong logic.

The computed property uses the modulus operator % to get the remainder when dividing by 2, then checks if it is equal to 0 with ==.

5fill in blank

hard

Fill all three blanks to create a computed property that returns the initials of a person in uppercase.

Swift

struct Person {
    var firstName: String
    var lastName: String
    var initials: String {
        return firstName[1].uppercased() + lastName[2].uppercased()
    }
}

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

Aprefix(1)

Bsuffix(1)

Cprefix(0)

DdropFirst()

Attempts:

3 left

💡 Hint

Common Mistakes

Using suffix(1) gets last letter, not initial.

Using prefix(0) returns empty string.

Using dropFirst() removes first letter instead of selecting it.

The computed property uses prefix(1) to get the first letter of each name, then converts it to uppercase.