iOS Development Swift Programming Language 2

Question 1

What is protocol-oriented programming in Swift?

Accepted Answer

Designing code around protocol definitions rather than class hierarchies

Answer

Protocol-oriented programming in Swift emphasizes defining behavior through protocols rather than relying on class inheritance.

Question 2

Which access control level in Swift restricts access to the same file?

Accepted Answer

fileprivate

Answer

`fileprivate` restricts the use of an entity to the same Swift source file where it is defined.

Question 3

What does `@escaping` mean on a closure parameter in Swift?

Accepted Answer

The closure can be stored and called after the function returns

Answer

An `@escaping` closure is allowed to outlive the function it was passed into, commonly used for async callbacks.

Question 4

What is a Swift struct compared to a class?

Accepted Answer

A value type that is copied on assignment

Answer

Swift structs are value types, so they are copied whenever they are assigned to a new constant, variable, or passed to a function.

Question 5

Which Swift operator is used for nil-coalescing?

Accepted Answer

??

Answer

The nil-coalescing operator `??` unwraps an optional and provides a default value if the optional is nil.

iOS Development Practice Test