For-in with where clause in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print only even numbers from the array.

Swift

let numbers = [1, 2, 3, 4, 5, 6]
for number in numbers where number [1] 2 == 0 {
    print(number)
}

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

A+

B%

C-

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' instead of '%' causes a syntax error.

Using '-' or '*' does not correctly check for even numbers.

The where clause filters numbers where the remainder when divided by 2 is zero, meaning even numbers.

2fill in blank

medium

Complete the code to print names that start with the letter 'A'.

Swift

let names = ["Alice", "Bob", "Anna", "Mark"]
for name in names where name.hasPrefix([1]) {
    print(name)
}

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

A"B"

B"M"

C"Z"

D"A"

Attempts:

3 left

💡 Hint

Common Mistakes

Using a letter other than 'A' will filter wrong names.

Forgetting quotes causes a syntax error.

The hasPrefix method checks if the string starts with the given substring. Here, we want names starting with 'A'.

3fill in blank

hard

Fix the error in the code to print numbers greater than 10.

Swift

let values = [5, 12, 18, 7, 3]
for val in values where val [1] 10 {
    print(val)
}

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

A>

B<

C==

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' or '<=' filters numbers less than or equal to 10.

Using '==' filters only numbers equal to 10.

The where clause should filter values greater than 10, so the operator must be '>'.

4fill in blank

hard

Fill both blanks to print words longer than 4 characters.

Swift

let words = ["apple", "dog", "banana", "cat"]
for word in words where word.[1] > [2] {
    print(word)
}

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

Acount

Blength

C4

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'length' is incorrect in Swift strings.

Comparing to 5 filters words longer than 5 characters, not 4.

The count property gives the length of the string. We compare it to 4 to find words longer than 4 characters.

5fill in blank

hard

Fill all three blanks to print numbers divisible by 3 and greater than 10.

Swift

let nums = [3, 9, 12, 15, 7, 20]
for num in nums where num [1] 3 == 0 && num [2] [3] {
    print(num)
}

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

A%

B>

C10

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' changes the filter condition.

Using incorrect operators causes syntax errors.

The modulo operator '%' checks divisibility by 3. The 'where' clause also checks if the number is greater than 10.