Set creation and operations in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an empty set of integers.

Swift

var numbers: Set<Int> = [1]

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

A[]

B{}

CArray()

DSet()

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets [] creates an empty array, not a set.

Using curly braces {} is invalid syntax for sets in Swift.

In Swift, an empty set is created using Set(). Using [] creates an empty array, and {} is not valid syntax for an empty set.

2fill in blank

medium

Complete the code to create a set with the elements 1, 2, and 3.

Swift

let digits: Set<Int> = [1]

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ASet(1, 2, 3)

BSet([1, 2, 3])

C[1, 2, 3]

D(1, 2, 3)

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to pass multiple arguments directly to Set initializer.

Using array literal without Set initializer.

To create a set with elements, you can pass an array to the Set initializer like Set([1, 2, 3]). Using just square brackets creates an array, and Set(1, 2, 3) is invalid syntax.

3fill in blank

hard

Fix the error in the code to check if two sets have any common elements.

Swift

let setA: Set<Int> = Set([1, 2, 3])
let setB: Set<Int> = Set([3, 4, 5])
let hasCommon = !setA.[1](setB).isEmpty

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Aintersection

Bunion

CsymmetricDifference

Dsubtracting

Attempts:

3 left

💡 Hint

Common Mistakes

Using union returns all elements from both sets, not just common ones.

Using symmetricDifference returns elements in either set but not both.

The intersection method returns the common elements between two sets. Checking if this intersection is not empty tells us if they share any elements.

4fill in blank

hard

Fill both blanks to create a set of even numbers from 1 to 10.

Swift

let numbers = Set(1...10)
let evenNumbers = numbers.filter { $0 [1] 2 [2] 0 }

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A%

B==

C!=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' instead of '==' causes odd numbers to be selected.

Using '>' does not check for evenness.

To find even numbers, use the modulo operator % to check if the remainder when divided by 2 is zero.

5fill in blank

hard

Fill all three blanks to create a dictionary from a set of words with their lengths, but only include words longer than 3 characters.

Swift

let words: Set<String> = Set(["apple", "cat", "banana", "dog"])
let wordLengths = [[1]: [2] for [3] in words if [2] > 3]

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Aword

Bword.count

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect variable names.

Not filtering words by length.

We create a dictionary where keys are words and values are their lengths. We iterate over each word in the set and include only those with length greater than 3.