Equatable, Hashable, Comparable protocols in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to make the struct conform to Equatable.

Swift

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

    static func ==(lhs: Point, rhs: Point) -> Bool {
        return lhs.x [1] rhs.x && lhs.y == rhs.y
    }
}

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

A+

B==

C!=

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' instead of '==' causes the comparison to be wrong.

Using '+' or '-' operators here does not make sense.

The == operator checks if both x and y are equal for two points.

2fill in blank

medium

Complete the code to make the struct conform to Hashable by implementing hash(into:).

Swift

struct Person: Hashable {
    var name: String
    var age: Int

    func hash(into hasher: inout Hasher) {
        hasher.[1](name)
        hasher.combine(age)
    }
}

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Aappend

Badd

Cinsert

Dcombine

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'append' or 'add' which are not methods of Hasher.

Forgetting to combine all properties.

The combine method adds the value to the hasher to create a hash.

3fill in blank

hard

Fix the error in the Comparable conformance by completing the less-than operator.

Swift

struct Rectangle: Comparable {
    var width: Int
    var height: Int

    static func < (lhs: Rectangle, rhs: Rectangle) -> Bool {
        return lhs.width [1] rhs.width
    }
}

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A<

B>

C==

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using > or >= reverses the comparison logic.

Using == does not define ordering.

The less-than operator < compares if the left width is smaller than the right width.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps words to their lengths only if length is greater than 3.

Swift

let words = ["apple", "cat", "banana", "dog"]
var lengths = [String: Int]()
for word in words {
    if word.[1] > 3 {
        lengths[word] = word.[2]
    }
}

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Acount

Blength

Csize

DlengthOf

Attempts:

3 left

💡 Hint

Common Mistakes

Using properties like 'length' or 'size' which do not exist in Swift strings.

Using different properties for the two blanks causes errors.

The count property gives the number of characters in a string.

5fill in blank

hard

Fill all three blanks to create a sorted array of unique names using Set and sorted().

Swift

let names = ["Anna", "Bob", "Anna", "Charlie"]
let uniqueSortedNames = Array([1](names)).[2]() [3] { $0 < $1 }

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ASet

Bsorted

Csorted(by:)

DArray

Attempts:

3 left

💡 Hint

Common Mistakes

Using sorted() without by: when a closure is provided causes errors.

Not converting back to Array if needed.

First, convert the array to a Set to remove duplicates. Then use sorted(by:) with a closure to sort ascending. Finally, Array converts the set back to an array.