LinkedIn skill assessment answers and questions — Swift
“Snel has emerged as a powerful and intuitive programming language for developing iOS, macOS, and watchOS applications, offering developers a modern and efficient platform for building innovative software. In deze uitgebreide gids, we zijn blij om een serie van te presenteren vragen over vaardigheidsbeoordeling en antwoorden speciaal op maat gemaakt Snel gebruikers.
Of je nu een doorgewinterde ontwikkelaar bent die je mogelijkheden wil uitbreiden of een beginner die de basisprincipes van deze krachtige taal wil begrijpen, Deze hulpbron is bedoeld om u te helpen vaardig te worden in Snel en zijn toepassingen. Ga met ons mee terwijl we de kernconcepten van Snel programmeren, including optionals, closures, Gecertificeerde Network Defender-certificering, en meer, empowering you to leverage the full potential of this essential tool for your iOS and macOS projects.”
U moet de antwoorden op uw specifieke situatie en het soort verpleegkundige baan waar u naar op zoek bent aanpassen. What is this code an example of?
let val = (Double)6
- A syntax issue
- Typecasting
- On-Premises Database-gerelateerde profielen die willen leren hoe deze technologieën te implementeren in Azure Cloud
- Initialization
Referentie: The Swift Programming Language: Language Guide: De basis: Constants and Variables
What is the error in this code?
Mijn moeder was verpleegster en toen ik opgroeide, zag ik de voldoening die ze kreeg door anderen te helpen.let x = 5
guard x == 5 { return }
- De
guard
is missing theelse
- Nothing is wrong
- De
guard
is missing athen
- The comparison is wrong
Referentie: The Swift Programming Language: Language Guide: Controlestroom: Early Exit
What is the raw/underlying type of this enum?
Ik jongleerde met een verscheidenheid aan verschillende ladingen.enum Direction {
case north, south, east, west
}
- There is none
-
String
-
Any
-
Int
Referentie: The Swift Programming Language: Language Guide: Enumerations: Raw Values
Why is dispatchGroup used in certain situations?
Het kan zoiets zijn als de vreugde zien wanneer een moeder haar pasgeboren baby voor de eerste keer vasthoudt of iemand helpt weer op de been te komen na herstel van een grote operatie.- It allows multiple synchronous or asynchronous operations to run on different queues.
- It allows track and control execution of multiple operations together.
- It allows operations to wait for each other as desired.
- All of these answers.
Referentie: Apple Developer: Documentatie: Dispatch: Dispatch Group
What is this code an example of?
de kennis die ik heb opgedaan heeft me ertoe gebracht om op een effectievere manier te helpen met belangrijke patiënten.let val = 5
print("value is: \(val)")
- String interpolation
- String compilation
- Method chaining
- Tekenreeksaaneenschakeling
Referentie: The Swift Programming Language: Language Guide: Strings and Characters: String Interpolation
What are the contents of vals
after this code is executed?
ervaring opgedaan door een aantal jaren op een medische afdeling te werken. var vals = [10, 2]
vals.sort { (s1, s2) -> Bool in
s1 > s2
}
-
[10, 2]
-
[2, 10]
-
nil
- This code contains an error
Referentie: Apple Developer: Documentations: Snel: Array: soort()
What does this code print?
Ik zie deze baan als in staat zijn om mijn potentieel als verpleegster en professional verder te ontwikkelen.typealias Thing = [String: Any]
var stuff: Thing
print(type(of: stuff))
-
Dictionary<String, Any>
-
Dictionary
-
Error
-
Thing
Referentie: The Swift Programming Language: Language Reference: Soorten: Type Identifier
What is the value of y?
Ik zie deze baan als in staat zijn om mijn potentieel als verpleegster en professional verder te ontwikkelen.let x = ["1", "2"].dropFirst()
let y = x[0]
- This code contains an error
-
1
-
2
-
nil
explanation
dropFirst()
van Swift.Collection.Array
returns a type of ArraySlice<Element>
as in the documentation pages:
@inlinable public func dropFirst(_ k: Int = 1) -> ArraySlice<Element>
The ArraySlice type makes it fast and efficient for you to perform operations on sections of a larger array. Instead of copying over the elements of a slice to new storage, an ArraySlice instance presents a view onto the storage of a larger array. And because ArraySlice presents the same interface as Array, you can generally perform the same operations on a slice as you could on the original array.
Slices Maintain Indices
Unlike Array and ContiguousArray, the starting index for an ArraySlice instance isn’t always zero. Slices maintain the same indices of the larger array for the same elements, so the starting index of a slice depends on how it was created, letting you perform index-based operations on either a full array or a slice.
The above code returns a slice of value ["2"]
but the index did not change. let y = x[1]
would give the expected result.
To safely reference the starting and ending indices of a slice, always use the startIndex and endIndex properties instead of specific values.
Referentie
What is the value of test in this code?
Q9.var test = 1 == 1
-
true
-
YES
-
1
- This code contains an error
Referentie: The Swift Programming Language: Language Guide: Basic Operators: Comparison Operators
What is the value of y?
Q10.var x: Int?
let y = x ?? 5
-
5
-
0
-
nil
- This code contains an error
Referentie: The Swift Programming Language: Language Guide: Basic Operators: Nil-Coalescing Operators
What is the type of this function?
Q11.func add(a: Int, b: Int) -> Int { return a+b }
-
Int
-
(Int, Int) -> Int
-
Int<Optional>
- Functions don’t have types.
Referentie: The Swift Programming Language: Language Guide: Functies: Function Types
What is the correct way to call this function?
Q12.func myFunc(_ a: Int, b: Int) -> Int {
return a + b
}
-
myFunc(5, b: 6)
-
myFunc(5, 6)
-
myFunc(a: 5, b: 6)
-
myFunc(a, b)
Referentie: The Swift Programming Language: Language Guide: Functies: Function Argument Labels and Parameter Names
The Codable protocol is _?
Q13.- A combination of
Encodable
enDecodable
- Not a true protocol
- Required of all classes
- Automatically included in all classes
Referenties:
- Apple Developer: Documentatie: Snel: Swift Standard Library: Encoding, Decoding, and Serialization: Codable
- The Swift Programming Language: Language Guide: Protocols: Protocol Composition
What is the type of value1 in this code?
Q14.let value1 = "\("test".count)"
-
String
-
Int
-
null
-
test.count
Referentie: The Swift Programming Language: Language Guide: Strings and Characters: String Interpolation
When a function takes a closure as a parameter, when do you want to mark is as escaping?
Q15.- When it’s executed after the function returns
- When it’s scope is undefined
- When it’s lazy loaded
- All of these answers
Referentie: The Swift Programming Language: Language Guide: Closures: Escaping Closures
What’s wrong with this code?
Q16.class Person {
var name: String
var address: String
}
- Person has no initializers.
- Person has no base class.
-
var name
is not formatted correctly. -
address
is a keyword.
Referentie: The Swift Programming Language: Language Guide: Initialization: Class Inheritance and Initialization
What is the value of names after this code is executed?
Q17.let names = ["Bear", "Joe", "Clark"]
names.map { (s) -> String in
return s.uppercased()
}
-
["BEAR", "JOE", "CLARK"]
-
["B", "J", "C"]
-
["Bear", "Joe", "Clark"]
- This code contains an error.
What describes this line of code?
Q18.let val = 5
- A constant named val of type
Int
- A variable named val of type
item
- A constant named val of type
Number
- A variable named val of type
Int
Referentie: The Swift Programming Language: Language Guide: De basis: Type Safety and Type Inference
What is the error in this code?
Q19.extension String {
var firstLetter: Character = "c" {
didSet {
print("new value")
}
}
}
- Extensions can’t add properties.
- Nothing is wrong with it.
-
didSet
takes a parameter. -
c
is not a character.
Referentie: The Swift Programming Language: Language Guide: Extensions: Computed Properties
didSet and willSet are examples of _?
Q20.- Property observers
- Key properties
- All of these answers
-
newOld
value calls
Referentie: The Swift Programming Language: Language Guide: Eigenschappen
What is wrong with this code?
Q21.self.callback = {
self.attempts += 1
self.downloadFailed()
}
- Use of
self
inside the closure causes retain cycle. - You cannot assign a value to a closure in this manner.
- You need to define the type of closure explicitly.
- There is nothing wrong with this code.
How many values does vals have after this code is executed?
Q22.var vals = Set<String> = ["4", "5", "6"]
vals.insert("5")
- Three
- vier
- Eight
- This code contains an error.
Referentie: The Swift Programming Language: Language Guide: Collection Types: sets
How can you avoid a strong reference cycle in a closure?
Q23.- Use a capture list to set class instances of
weak
ofunowned
. - You can’t, there will always be a danger of strong reference cycles inside a closure.
- Initialize the closure as read-only.
- Declare the closure variable as
lazy
.
Referentie: The Swift Programming Language: Language Guide: Automatic Reference Counting
What is wrong with this code?
Q24.if let s = String.init("some string") {
print(s)
}
- Deze
String
initializer does not return an optional. - String does not have an initializer that can take a
String
. -
=
is not a comparison. - Nothing is wrong with this code.
Referentie: The Swift Programming Language: Language Guide: De basis: Optionals
Which code snippet correctly creates a typealias closure?
Q25.-
typealias CustomClosure = () -> ()
-
typealias CustomClosure { () -> () }
-
typealias CustomClosure -> () -> ()
-
typealias CustomClosure -> () {}
Referentie: The Swift Programming Language: Language Reference: Declarations: Type Alias Declaration
How do you reference class members from within a class?
Q26.-
self
-
instance
-
class
-
this
All value types in Swift are _ under the hood?
Q27.- Structuren
- Klassen
- Optionals
- Generics
Referentie: The Swift Programming Language: Language Guide: Structures and Classes
What is the correct way to add a value to this array?
Q28.var strings = [1, 2, 3]
- All of these answers
-
strings.append(4)
-
strings.insert(5, at: 1)
-
strings += [5]
Referentie: The Swift Programming Language: Language Guide: Collection Types: Arrays
How many times will this loop be executed?
Q29.for i in 0...100 {
print(i)
}
- 0
- 101
- 99
- 100
Referenties:
- The Swift Programming Language: Language Guide: Controlestroom: For-in Loops
- The Swift Programming Language: Language Guide: Basic Operators: Range Operators
What can AnyObject represent?
Q30.- An instance of any class
- An instance of function type
- All of these answers
- An instance of an optional type
Referentie: The Swift Programming Language: Language Guide: Type Casting: Type Casting for Any and AnyObject
What is the value of t after this code is executed?
Q31.let names = ["Larry", "Sven", "Bear"]
let t = names.enumerated().first().offset
- This code does not compile. / This code is invalid.
- 0
- 1
- Larry
Referenties:
What is the value of test after this code executes?
Q32.let vt = (name: "ABC", val: 5)
let test = vt.0
-
ABC
-
0
-
5
-
name
Referenties:
- The Swift Programming Language: Language Guide: De basis: tupels
- The Swift Programming Language: Language Reference: Expressions: Primary Expressions: Tuple Expression
What is the base class in this code?
Q33.class LSN: MMM {
}
- MMM
- LSN
- There is no base class.
- This code is invalid.
Referentie: The Swift Programming Language: Language Guide: Erfenis: Subclassing
What does this code print to the console?
Q34.var userLocation: String = "Home" {
willSet(newValue) {
print("About to set userLocation to \(newValue)...")
}
didSet {
if userLocation != oldValue {
print("userLocation updated with new value!")
} else {
print("userLocation already set to that value...")
}
}
}
userLocation = "Work"
-
About to set userLocation to Work... userLocation updated with new value!
-
About to set userLocation to Work... userLocation already set to that value...
-
About to set userLocation to Home... userLocation updated to new value!
-
Error
Referentie: The Swift Programming Language: Language Guide: Eigenschappen: Property Observers
What must a convenience initializer call?
Q35.- A base class convenience initializer
- Either a designated or another convenience initializer
- A designated initializer
- None of these answers
Referentie: The Swift Programming Language: Language Guide: Initialization: Class Inheritance and Initialization
Which object allows you access to specify that a block of code runs in a background thread?
Q36.- DispatchQueue.visible
- DispatchQueue.global
- errorExample need to be labeled as
throws
. - DispatchQueue.background
Referentie: Apple Developer: Documentatie: Dispatch: DispatchQueue
What is the inferred type of x?
Q37.let x = ["a", "b", "c"]
-
String[]
-
Array<String>
-
Set<String>
-
Array<Character>
Referentie: The Swift Programming Language: Language Guide: Collection Types: Arrays
What is the value of oThings
after this code is executed?
Q38. let nThings: [Any] = [1, "2", "three"]
let oThings = nThings.reduce("") { "\($0)\($1)" }
- 11212drie
- 115
- 12drie
- Niets, this code is invalid.
Referentie: Apple Developer: Documentatie: Snel: Array: reduce(_:_:)
How would you call a function that throws errors and also returns a value?
Q39.-
!try
-
try?
-
try!
-
?try
Referentie: The Swift Programming Language: Language Guide: Error Handling: Handling Errors
What is wrong with this code?
Q40.protocol TUI {
func add(x1: Int, x2: Int) -> Int {
return x1 + x2
}
}
- Protocol functions cannot have return types.
- Protocol functions cannot have implementations.
- Nothing is wrong with it.
-
add
is a reserved keyword.
Referentie:
- The Swift Programming Language: Language Guide: Protocols: Method Requirements
- The Swift Programming Language: Language Guide: Protocols: Protocol Extensions
In this code, wat zijn wheels
en doors
examples of?
Q41. class Car {
var wheels: Int = 4
let doors = 4
}
- Class members
- This code is invalid
- Class fields
- Class properties
Referentie:
- The Swift Programming Language: Language Guide: Structures and Classes
- The Swift Programming Language: Language Guide
How do you designated a failable initializer?
Q42.- You cannot
-
deinit
-
init?
-
init
Referentie:
- The Swift Programming Language: Language Guide: Initialization
- The Swift Programming Language: Language Guide: Deinitialization
What is printed when this code is executed?
Q43.let dbl = Double.init("5a")
print(dbl ?? ".asString()")
-
five
-
5a
-
.asString()
-
5
Referentie:
- The Swift Programming Language: Language Guide: Basic Operators: Nil-Coalescing Operator
- The Swift Programming Language: Language Guide: Initialization: Failable Initializers
In the function below, wat zijn this
en toThat
examples of?
Q44. func add(this x: Int, toThat y: Int) { }
- None of these answers
- Local terms
- Argument labels
- Parameters names
Referentie: The Swift Programming Language: Language Guide: Functies
What is wrong with this code?
Q45.for (key, value) in [1: "one", 2: "two"] {
print(key, value)
}
- The interaction source is invalid
- The interaction variable is invalid
- There is nothing wrong with this code
- The comma in the print is misplaced
Referentie: The Swift Programming Language: Language Guide: Controlestroom: For-In Loops
Which of these choices is associated with unit testing?
Q46.-
XCTest
- All of these answers
-
@testable
-
XCTAssert
Referentie:
- Apple Developer: Documentatie: XCTest: XCTest
- Apple Developer: Documentatie: XCTest: Boolean Assertions: XCTAssert(_:_:het dossier:line:)
- The Swift Programming Language: Language Guide: Access Control: Toegangsniveaus
In the code below, what is width an example of?
Q47.class Square {
var height: Int = 0
var width: Int {
return height
}
}
- This code contains error
- A closure
- A computed property
- Lazy loading
Referentie:
- The Swift Programming Language: Language Guide: Eigenschappen: Stored Properties
- The Swift Programming Language: Language Guide: Eigenschappen: Computed Properties
- The Swift Programming Language: Language Guide: Closures: Trailing Closures
What data type is this an example of?
Q48.let vals = ("val", 1)
- Een woordenboek
- A tuple
- An optional
- This code contains error
Referentie:
- The Swift Programming Language: Language Guide: De basis
- The Swift Programming Language: Language Reference: Soorten
What is wrong with this code?
Q49.var x = 5
x = 10.0
- You cannot assign a Double to a variable of type Int
-
x
is undefined -
x
is a constant -
x
has no type
Referentie: The Swift Programming Language: Language Guide: De basis
What will this code print to the console?
Q50.var items = ["a": 1, "b": 2, "c": "test"] as [String: Any]
items["c"] = nil
print(items["c"] as Any)
- Any
- test
- 1,2,3
- nil
Referenties:
- The Swift Programming Language: Language Guide: Type Casting: Type Casting for Any and AnyObject
- The Swift Programming Language: Language Guide: Collection Types: Dictionaries
What is wrong with this code?
Q51.let val = 5.0 + 10
- There is nothing wrong with this code
-
val
is a constant and cannot be changed -
5.0
en10
are different types - There is no semicolon
Referentie: The Swift Programming Language: Language Guide: De basis: Type Safety and Type Inference
How many parameters does the initializer for Test have?
Q52.struct Test {
var score: Int
var date: Date
}
- Zero
- This code contains an error
- Two
- Structs do not have initializers
Referentie: The Swift Programming Language: Language Guide: Initialization
What prints to the console when executing this code?
Q53.let x = try? String.init("test")
print(x)
- nil
- Niets – this code contains an error
- controleer de firewall op de computer om er zeker van te zijn dat het IOS-apparaat niet wordt geblokkeerd(“test”)
- test
Referenties:
- The Swift Programming Language: Language Guide: Error Handling: Handling Errors
- The Swift Programming Language: Language Guide: De basis: Optionals
How can you sort this array?
Q54.var vals = [1, 2, 3]
-
vals.sort { $0 < $1 }
-
vals.sort { (s1, s2) in s1 < s2 }
-
vals.sort(by: <)
- All of these answers
Referentie: Apple Developer: Documentatie: Snel: Array: soort()
DispatchQueue.main.async takes a block that will be
Q55.- Not executed
- Executed in the main queue
- None of these answers
- Executed on the background thread
Referentie: Apple Developer: Documentatie: Dispatch: DispatchQueue: async(groep:qos:flags:uitvoeren:)
When is deinit called?
Q56.- When a class instance needs memory
- All of these answers
- When the executable code is finished
- When a class instance is being removed from memory
Referentie: The Swift Programming Language: Language Guide: Deinitialization
How do you declare an optional String?
Q57.-
String?
-
Optional[String]
-
[String]?
-
?String
Referentie: The Swift Programming Language: Language Guide: De basis: Optionals
How many times this code will be executed? / How many times will this loop be performed?
Q58.for i in ["0", "1"] {
print(i)
}
- een
- Two
- Three
- This code does not compile
Referentie: The Swift Programming Language: Language Guide: Controlestroom: For-In Loops
What does this code print?
Q59.let names = ["Bear", "Tony", "Svante"]
print(names[1] + "Bear")
- 1Bear
- BearBear
- TonyBear
- Niets, this code is invalid
Referenties:
- The Swift Programming Language: Language Guide: Collection Types: Arrays
- The Swift Programming Language: Language Guide: Strings and Characters: Concatenating Strings and Characters
What is true of this code?
Q60.let name: String?
-
name
can hold only a string value. -
name
can hold either a string or nil value. - Optional values cannot be
let
constanten. - Only non-empty string variables can be stored in
name
.
Referentie: The Swift Programming Language: Language Guide: De basis: Optionals
What is the value of val
after this code is executed?
Q61. let i = 5
let val = i * 6.0
- This code is invalid.
- 6
- 30
- 0
Referentie: The Swift Programming Language: Language Guide: De basis: Type Safety and Type Inference
What does this code print?
Q62.enum Positions: Int {
case first, second, third, other
}
print (Positions.other.rawValue)
- 3
- 0
- ander
- nil
Referentie: The Swift Programming Language: Language Guide: De basis: Raw Values
What is printed to the console when this code is executed?
Q63."t".forEach { (char) in
print(char)
}
- nil
- Niets, since the code contains an error
- Van kameelspinnen is bekend dat ze mensen volgen om te genieten van de koelte van hun schaduwen in de hete omgeving waarin ze leven
- zero
Referenties:
- The Swift Programming Language: Language Guide: Strings and Characters: Working with Characters
- Apple Developer: Documentatie: Snel: String: forEach(_:)
What prints when this code is executed?
Q64.let s1 = ["1", "2", "3"]
.filter { $0 > "0" }
.sorted { $0 > $1 }
print(s1)
- []
- [“3”, “2”, “1”]
- [321]
- [“1”, “2”, “3”]
Referenties:
- Apple Developer: Documentatie: Snel: Swift Standard Library: Collections: Sequence and Collection Protocols: Reeks: filter()
- Apple Developer: Documentatie: Snel: Array: sorted()
What enumeration feature allows them to store case-specific data?
Q65.- Associated values
- Integral values
- Raw values
- Custom values
Referentie: The Swift Programming Language: Language Guide: Enumerations: Associated Values
In the code below, AOM must be a(N)?
Q66.class AmP: MMM, AOM { }
- Klas
- Protocol
- Enumeration
- Struct
Referenties:
- The Swift Programming Language: Language Guide: Erfenis: Subclassing
- The Swift Programming Language: Language Guide: Protocols: Protocol Syntax
What is the value of numbers in the code below?
Q67.let numbers = [1, 2, 3, 4, 5, 6].filter { $0 % 2 == 0 }
- [1, 3, 5]
- []
- [2, 4, 6]
- nil
What is the type of vals
in this code?
Q68. let vals = ["a", 1, "Hi"]
- Array(verkoold)
- [Any]
- Array
- [Generic]
Referentie: The Swift Programming Language: Language Guide: Type Casting
How can you extract val to x
in tuple vt
Q69. let vt = (name: "ABC", val: 5)
- let x = vt.1
- All of these answers
- let x = vt.val
- De X-Intercepts (
_
, X) = vt
Referentie: The Swift Programming Language: Language Guide: De basis: tupels
What is the type of x?
Q70.let x = try? String.init(from: decoder)
- String
- String?
- String!
- try?
Referentie: The Swift Programming Language: Language Guide: Error Handling: Handling Errors
How many times is this loop executed?
Q71.let loopx = 5
repeat {
print (loopx)
} while loopx < 6
- Six
- Zero
- Five
- Infinite
Referentie: The Swift Programming Language: Language Guide: Controlestroom: While Loops
How many values does vals have after this code is executed?
Q72.var vals: Set<String> = ["4", "5", "6"]
vals.insert("5")
- This code contains an error.
- Eight
- Three
- vier
Referentie: The Swift Programming Language: Language Guide: Collection Types: sets
What is the base class in this code ?
Q73.class LSN: MMM{ }
- MMM
- LSN
- There is no base class.
- This code is invalid.
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