Swift REPL and Playgrounds - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print "Hello, Swift!" in a Playground.

Swift

print([1])

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

A'Hello, Swift!'

B"Hello, Swift!"

CHello, Swift!

DHello Swift

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to use quotes around the string.

Using single quotes instead of double quotes.

In Swift, strings must be enclosed in double quotes to be printed correctly.

2fill in blank

medium

Complete the code to declare a variable named 'count' with value 10 in Swift REPL.

Swift

var count = [1]

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

A"10"

Bcount

Cten

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Putting numbers inside quotes, which makes them strings.

Using variable names instead of values.

Variables holding numbers should be assigned numeric values without quotes.

3fill in blank

hard

Fix the error in the code to add two numbers and print the result.

Swift

let sum = 5 [1] 3
print(sum)

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

A+

B-

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction or multiplication instead of addition.

Using invalid operators.

The plus sign (+) adds two numbers in Swift.

4fill in blank

hard

Fill both blanks in the loop to build a dictionary that maps words to their lengths for words longer than 3 characters. (Assume `let words = ["hello", "hi", "world", "a"]` is defined.)

Swift

var lengths: [String: Int] = [:]
for word in words {
  if word.count > 3 {
    lengths[[1]] = [2]
  }
}

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

Aword

Bword.count

Cword.length

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'word.length' which is not valid in Swift (use .count).

Using 'count' alone without specifying the word.

In Swift, use a for loop to build the dictionary, with 'word' as key and 'word.count' as value.

5fill in blank

hard

Fill all three blanks in the loop to create a dictionary from a list of tuples where keys are uppercase and values are doubled. (Assume `let data: [(String, Int)] = [("apple", 5), ("banana", 3)]` is defined.)

Swift

var transformed: [String: Int] = [:]
for ([3], [2]) in data {
  transformed[[1].uppercased()] = [2] * 2
}

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

Akey

Bvalue

Dval

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names that don't match between the tuple and usage.

Not uppercasing the key or doubling the value.

Using 'val' instead of 'value'.

Use 'key' for the first and third blanks to access the tuple key, and 'value' for the second blank to double the value. Note the tuple destructuring in the for loop.