Where clauses for complex constraints in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to filter numbers greater than 10 using a where clause.

Swift

let numbers = [5, 12, 7, 20, 3]
let filtered = numbers.filter { number in
    number [1] 10
}

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

A<

B<=

C>

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > causes wrong filtering.

Using == filters only numbers equal to 10.

The where clause filters numbers greater than 10, so the operator should be >.

2fill in blank

medium

Complete the code to filter strings with length less than 5 using a where clause.

Swift

let words = ["apple", "cat", "banana", "dog"]
let shortWords = words.filter { word in
    word.count [1] 5
}

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

A<

B>=

C==

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using > or >= filters longer words.

Using == filters only words with exactly 5 characters.

The where clause filters words with length less than 5, so the operator should be <.

3fill in blank

hard

Fix the error in the where clause to filter even numbers.

Swift

let nums = [1, 2, 3, 4, 5, 6]
let evens = nums.filter { num in
    num [1] 2 == 0
}

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

A%

B/

C*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using / divides the number and returns a quotient, not remainder.

Using * or + does not check evenness.

The modulo operator % checks if the remainder is zero, which means the number is even.

4fill in blank

hard

Fill both blanks to filter words starting with 'a' and having length greater than 3.

Swift

let words = ["apple", "ant", "bat", "arc", "axe"]
let filtered = words.filter { word in
    word.hasPrefix([1]) && word.count [2] 3
}

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

A"a"

B"b"

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong prefix string filters wrong words.

Using < filters shorter words, not longer.

The prefix should be "a" and length should be greater than 3, so > is correct.

5fill in blank

hard

Fill all three blanks to create a dictionary of words with their lengths, filtering words longer than 4 characters.

Swift

let words = ["swift", "code", "play", "learn"]
let wordLengths = [[1]: [2] for word in words where word.count [3] 4]

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

Aword

Bword.count

C>

Dword.length

Attempts:

3 left

💡 Hint

Common Mistakes

Using word.length is invalid in Swift.

Using < filters shorter words, not longer.

The dictionary keys are words, values are their counts, and filter uses > 4 for length.