Why API integration connects to servers in iOS Swift - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a URL session for API calls.

iOS Swift

let session = URLSession[1]

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

A.main

B.background

C.default

D.shared

Attempts:

3 left

💡 Hint

Common Mistakes

Using .default or .main instead of .shared causes errors.

The URLSession.shared is the shared singleton session used for simple API calls.

2fill in blank

medium

Complete the code to create a URL object from a string.

iOS Swift

guard let url = URL(string: [1]) else { return }

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

A"https://api.example.com/data"

Bhttps://api.example.com/data

CurlString

DURL(string: "https://api.example.com/data")

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a variable name without quotes or a URL object instead of a string.

The URL initializer requires a string literal or variable wrapped in quotes.

3fill in blank

hard

Fix the error in the code to start a data task.

iOS Swift

let task = session.dataTask(with: url) { data, response, error in
  guard error == [1] else { return }
  // process data
}
task.resume()

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

A0

Btrue

Cnil

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Checking error == true or error == false causes logic errors.

When there is no error, the error variable is nil.

4fill in blank

hard

Fill both blanks to parse JSON data safely.

iOS Swift

if let data = data {
  let json = try? JSONSerialization.[1](with: data, options: [2])
  // use json
}

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AjsonObject

BjsonArray

C.allowFragments

DmutableContainers

Attempts:

3 left

💡 Hint

Common Mistakes

Using jsonArray instead of jsonObject or wrong options causes parsing errors.

Use jsonObject to parse JSON and .allowFragments to allow top-level fragments.

5fill in blank

hard

Fill all three blanks to send a GET request with URLRequest.

iOS Swift

var request = URLRequest(url: [1])
request.httpMethod = [2]
request.addValue([3], forHTTPHeaderField: "Content-Type")

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

Aurl

B"GET"

C"application/json"

D"POST"

Attempts:

3 left

💡 Hint

Common Mistakes

Using "POST" instead of "GET" or wrong header values.

Use the URL variable for the request URL, set method to "GET", and content type to "application/json".