iOS Development For Beginners 3

Question 1

In Swift, which keyword declares a constant whose value cannot change?

Accepted Answer

let

Answer

The 'let' keyword declares an immutable constant in Swift.

Question 2

Which keyword declares a variable that can be changed later in Swift?

Accepted Answer

var

Answer

The 'var' keyword declares a mutable variable in Swift.

Question 3

What is an Optional in Swift?

Accepted Answer

A type that can hold either a value or nil

Answer

An Optional represents a value that may be present or absent (nil).

Question 4

Which symbol is used to mark a type as Optional in Swift?

Accepted Answer

?

Answer

A trailing question mark (e.g., String?) marks a type as Optional.

Question 5

What does the 'func' keyword do in Swift?

Accepted Answer

Declares a function

Answer

The 'func' keyword is used to define a function in Swift.

iOS Development Practice Test