Computer SCI
What is the difference between += and append() when adding elements to an array in Swift?
+= adds an array of elements to an array, while append() adds a single element.
What is the output of the following code snippet? let nums = [1, 2, 3, 4, 5] let result = nums.reduce(0, { x, y in x + y }) print(result)
15
What is the output of the following code? let nums = [1, 2, 3, 4, 5] let result = nums.reduce(0) { $0 + $1 } print(result)
15
Which operator is used for optional chaining in Swift?
?
What is a protocol in Swift?
A blueprint for a class, struct, or enumeration
What is an @escaping closure in Swift?
A closure that can be passed as an argument to another function and executed asynchronously.
What is a computed property in Swift?
A property that is computed based on the value of one or more other properties.
What is a lazy property in Swift?
A property that is initialized only when it is first accessed.
What is Not a function of Swift programming
Dynamic Typing
What is the output of the following code? let name = "John" let greeting = "Hello, \(name)!" print(greeting)
Hello, John!
What does the defer keyword do in Swift?
It executes a block of code after a function returns.
Which of the following statements is true about Swift's guard statement?
It is used for exiting a scope early in Swift.
What is Not a data type of Swift
Long
Which of the following statements is true about optionals in Swift?
Optionals can be used with any data type.
Which of the following is not a property of a class in Swift?
Procedures
What is the difference between a struct and a class in Swift?
Structs are value types while classes are reference types
What is the output of the following code? let num = 5 if case 1...10 = num { print("The number is between 1 and 10") } else { print("The number is not between 1 and 10") }
The number is between 1 and 10
Which of the following is not a feature of optionals in Swift?
They are automatically unwrapped
Which of the following is not a feature of a structure in Swift?
They can be inherited from other structures
What is the purpose of guard statement in Swift?
To check for a condition and exit early if it's not met
Var is used to define a variable. T or F
True
Which of the following is not a collection type in Swift?
Tuple
Which among the following is the feature of tuple in Swift?
Tuples can be decomposed into individual variables The values within a tuple can be of any type A tuple type is a comma-separated list of types, enclosed in parentheses.
Which of the following is not a way to unwrap an optional in Swift?
Using the "?" operator
Which keyword is used to define a class in Swift?
class
Which method is used to extract values of a given type from an Array in Swift?
flatMap
Which keyword is used to define a closure in Swift?
func
Which keyword is used to define a function in Swift?
func
Which of the following is NOT a correct way to declare a function in Swift?
func increment(_ num: Int) -> { num + 1 }
Which keyword makes the enum store its payload with a layer of indirection in Swift?
indirect
Which among the following is false with respect to map in Swift?
iterates through array
Which keyword is used to declare a constant in Swift?
let
How to define an array with repeated values?
let arrayOfStrings = Array(repeating: "Swift",count: 4)
Which of the following is NOT a correct way to declare an array in Swift?
let names = Array<String>(["Alice", "Bob", "Charlie"])
Which keyword enables a method of a struct to change the value of the struct itself in swift?
mutating
How to conver the given String to uppercase in Swift? Given let string = "HhEeLlLlOo"
string.uppercased()
Which type are arrays in Swift?
value
Which of the following is not a valid way to define an optional in Swift?
var bool: Optional<Bool>
What is the difference between while and repeat-while loops in Swift?
while checks the condition at the beginning of the loop, while repeat-while checks it at the end of the loop.
Which of the following is not a control flow statement in Swift?
while-do