Comments and documentation markup in Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of comments in Swift code?

Comments explain the code to humans. They help others (and yourself) understand what the code does without affecting how the program runs.

beginner

How do you write a single-line comment in Swift?

Use two slashes // before the comment text. Everything after // on that line is ignored by the compiler.

beginner

How do you write a multi-line comment in Swift?

Start with /* and end with */. Everything between is treated as a comment, even if it spans many lines.

intermediate

What is documentation markup in Swift and why is it useful?

Documentation markup uses special comment styles (like ///) to create structured notes. These notes can be shown in code editors to explain functions, parameters, and return values clearly.

intermediate

Give an example of a documentation comment for a Swift function.

/// Adds two numbers and returns the result.
/// - Parameters:
///   - a: The first number.
///   - b: The second number.
/// - Returns: The sum of a and b.

Which symbol starts a single-line comment in Swift?

A #

B //

C /*

D <!--

Single-line comments in Swift start with //. Multi-line comments use /* ... */.

What does the following Swift comment style /// indicate?

A A compiler directive

B A single-line comment

C A multi-line comment start

D A documentation comment for code explanation

/// is used for documentation comments that provide structured information about code elements.

How do multi-line comments behave in Swift?

A They start with <code>/*</code> and end with <code>*/</code>

B They start with <code>//</code> and end with a blank line

C They start with <code>///</code> and end with <code>///</code>

D They start with <code>#</code> and end with <code>#</code>

Multi-line comments in Swift are enclosed between /* and */.

Why should you use documentation comments in your Swift code?

A To help others understand your code with clear explanations

B To make the code run faster

C To hide code from the compiler

D To change the code's logic

Documentation comments improve code readability and help others (and yourself) understand how to use your code.

Which of these is NOT a valid Swift comment style?

A /// This is a documentation comment

B /* This is a comment */

C <!-- This is a comment -->

D // This is a comment

is an HTML comment style, not valid in Swift.

Explain the difference between single-line, multi-line, and documentation comments in Swift.

Think about how each comment type looks and what it is used for.

Write a documentation comment for a Swift function that multiplies two numbers and returns the result.

Follow the Swift documentation comment format with clear sections.