Variadic parameters in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a function that accepts a variable number of integers.

Swift

func sum(numbers: [1]) -> Int {
    return numbers.reduce(0, +)
}

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

A...

B...Int

C...Ints

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the three dots (...) before the type.

Using plural forms like Ints which is invalid syntax.

The ...Int syntax defines a variadic parameter that accepts zero or more integers.

2fill in blank

medium

Complete the code to call the variadic function with three integer arguments.

Swift

let result = sum(numbers: [1])

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

A1, 2, 3

B[1, 2, 3]

C(1, 2, 3)

D"1, 2, 3"

Attempts:

3 left

💡 Hint

Common Mistakes

Passing an array instead of comma-separated values.

Passing a tuple or string instead of separate values.

Variadic parameters are passed as comma-separated values, not as arrays or tuples.

3fill in blank

hard

Fix the error in the function definition to correctly accept a variable number of strings.

Swift

func greet(names: [1]) {
    for name in names {
        print("Hello, \(name)!")
    }
}

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

A...Strings

B...

C...String

Attempts:

3 left

💡 Hint

Common Mistakes

Using plural type names like Strings.

Omitting the three dots.

The correct syntax for variadic parameters requires three dots before the type, like ...String.

4fill in blank

hard

Fill both blanks to create a function that returns the average of a variable number of Double values.

Swift

func average(values: [1]) -> Double {
    let total = values[2]reduce(0.0, +)
    return total / Double(values.count)
}

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

A...

B...Double

C.

D?

Attempts:

3 left

💡 Hint

Common Mistakes

Using a question mark instead of a dot before reduce.

Omitting the three dots in the parameter.

The variadic parameter uses ...Double. To call reduce on the array, use the dot operator ..

5fill in blank

hard

Fill all three blanks to define and call a function that prints all provided strings separated by commas.

Swift

func printAll(items: [1]) {
    let combined = items[2]joined(separator: [3])
    print(combined)
}

printAll(items: "apple", "banana", "cherry")

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

A...String

B.

C", "

D...

Attempts:

3 left

💡 Hint

Common Mistakes

Using '...' instead of '...String' in the parameter.

Forgetting the dot before joined.

Using wrong separator string.

The function uses ...String for variadic parameters. The joined(separator:) method is called with a dot and a string separator ", ".