Refined Swift Test - 72+ MCQs: Swift Programming Language Quiz: Test Your Swift Skills

1. Explain Swift's 'map', 'filter', and 'reduce' functions.

Predefined mathematical functions in Swift

Functions for handling errors in Swift

Functions for working with arrays, providing transformations, filtering, and combining elements

Syntax sugar for defining Swift properties

2. Which Swift keyword is used to check multiple conditions in an 'if' statement?

and

multiif

else

3. What is the 'escaping' keyword used for in Swift?

To indicate a closure parameter that outlives the function it's passed to

To create an escaping type

To escape from a loop

To escape from an optional

4. What is the purpose of the 'if' statement in Swift?

To create a loop

To define a function

To make decisions based on conditions

To import external libraries

5. How can you achieve thread safety in Swift?

By using global variables

By defining multiple classes

Through the use of locks and queues

Swift does not support thread safety

6. Explain the concept of protocol-oriented programming in Swift.

A paradigm emphasizing composition through protocols

A method for writing Swift protocols

An approach to writing procedural Swift code

A way to organize Swift classes hierarchically

7. How does Swift handle multiple return values from a function?

Through the use of tuples

By using global variables

Swift does not support multiple return values

By defining multiple functions

8. What is the correct way to check if two strings are not equal in Swift?

string1 <> string2

string1 != string2

string1 ~= string2

string1 .notEqual(string2)

9. What is the correct syntax for an 'if-else' statement in Swift?

if condition { } else { }

if { } else { }

if (condition) { } else { }

if-else condition { }

10. Which Swift keyword is used to indicate the absence of a value?

nil

void

none

empty

11. What are closures in Swift?

A way to represent a sequence of values in Swift

A mechanism for capturing and storing references to variables and constants

A feature for defining custom attributes in Swift

A set of predefined functions in Swift for handling errors

12. How is 'protocol-oriented programming' emphasized in Swift?

By using only classes

By focusing on protocols for building types

By avoiding protocols altogether

By using only functions

13. How do you declare a property as 'weak' in Swift?

weak var myProperty: Type?

myProperty weak Type?

let myProperty: weak Type?

var myProperty: weak Type?

14. In Swift, what is the purpose of the 'guard' statement?

To unwrap optionals

To check for nil and else execute the code

To force unwrap optionals

To provide a default value for optionals

15. What is the purpose of the 'enum' keyword in Swift?

To define a class

To represent an enumeration

To create a function

To declare a protocol

16. In Swift, what is the purpose of the 'subscript' keyword?

To define a subscript operator for accessing elements in a collection

To create a new subscript type

To define a function with variable parameters

To perform bitwise subtraction

17. How does Swift handle memory management for reference types?

Through automatic reference counting (ARC)

By using garbage collection

Memory management is the responsibility of the developer

Swift doesn't support reference types

18. In Swift, what is the purpose of the 'while' loop?

To repeat a block of code a specific number of times

To iterate over elements in an array

To make decisions based on conditions

To create an infinite loop

19. What is the correct way to concatenate two strings in Swift?

string1 + string2

string1 .concat(string2)

concatenate(string1, string2)

string1 .append(string2)

20. In Swift, how do you create an empty array of integers?

var myArray: [Int]

array myArray = []

let myArray = [Int]

emptyArray myArray: Int[]

21. What is the purpose of the Swift 'enum' type?

To define a set of related values

To declare a constant in Swift

To represent a single value

Swift does not have an 'enum' type

22. In Swift, how do you use a closure to sort an array of integers in ascending order?

array.sort { $1 > $0 }

array.sort { $0 < $1 }

array.sort { $0 > $1 }

array.sort { $1 < $0 }

23. What is the purpose of the 'guard' statement in Swift?

To declare a constant

To create a loop

To check for nil and else execute the code

To define a function

24. What is the purpose of the 'associatedtype' keyword in Swift protocols?

To specify a default implementation

To declare a typealias within a protocol

To enforce a required initializer

To associate a type with a protocol

25. Which Swift data type is used to store decimal numbers?

Int

Double

Float

Decimal

26. How can you handle errors in Swift?

By using global variables

By defining multiple classes

Through the use of the 'try', 'catch', and 'throw' keywords

Swift does not support error handling

27. How does Swift handle optionals and unwrapping?

Optionals in Swift are automatically unwrapped

By using the 'try' keyword

Through forced unwrapping using '!'

Swift does not have optionals

28. Explain Swift's 'associatedtype' in protocols.

A keyword for defining Swift functions in protocols

A mechanism for specifying the type of an associated value in Swift

An alternative syntax for defining Swift properties

A way to declare global constants in Swift

29. What is the purpose of an optional in Swift?

To handle errors

To define a default value

To represent a value that may or may not be present

To declare a constant value

30. What is the purpose of the 'extension' keyword in Swift?

To extend the size of a data type

To add new functionality to an existing type

To create a new class

To override a base class method

Swift MCQ Test 3