Question

How are documentation comments different from other types of comments?

Short answer

The key difference between documentation comments and other types of comments is their purpose and syntax. Documentation comments are specifically designed to generate documentation from the source code, whereas other comments (single-line and multi-line) are used for explanations and communication within the code itself. Documentation comments have special syntax and can include tags, while other comments have a simpler syntax and do not include tags.

Step-by-step solution

Define documentation comments

Documentation comments are special comments that are specifically designed to generate documentation from the source code. These comments usually begin with a special delimiter (for example, in Java, they start with /** and end with */) and contain additional tags to better describe various aspects of the code.

Define other types of comments

Other types of comments include single-line comments and multi-line comments. Single-line comments are used to add brief explanations or notes within the code and usually start with a specific character or sequence of characters (for example, in Java and Python, they start with //). Multi-line comments are used for longer explanations or temporarily removing blocks of code and are enclosed by specific delimiters (for example, in Java, they start with /* and end with */, while in Python they start with ''' or """ and end with the same characters).

Compare documentation comments and other types of comments

The main difference between documentation comments and other types of comments is their purpose. Documentation comments are intended to generate documentation automatically, whereas other comments are used for explanations and communications within the code itself. Additionally, documentation comments have special syntax and can include tags, while other comments do not.

Provide examples

Here are examples of each type of comment in Java: Documentation comment: ``` /** * This method calculates the sum of two numbers. * * @param a The first number to add. * @param b The second number to add. * @return The sum of a and b. */ public int add(int a, int b) { return a + b; } ``` Single-line comment: ```java // This is a single-line comment. int x = 5; ``` Multi-line comment: ```java /* * This is a multi-line comment. * It can span multiple lines. */ int y = 10; ```

Key concepts

Documentation Comments

Documentation comments are unique in their function and format, especially in Java, as they are designed to generate automated documentation from code. This form of commenting is initiated with `/**` and terminated with `*/`. These comments can include special tags, such as `@param` and `@return`, which are used to describe the code in a more detailed and formal way. These tags help generate organized and user-friendly documentation, often used to create HTML-based references with tools like Javadoc.

With documentation comments, developers can ensure that the intended use, parameters, and return values of a method or function are clearly defined. They are integral to maintainability, as they provide a comprehensive guide for anyone using or maintaining the code. Instead of focusing on how the code works internally, documentation comments communicate the purpose and usage of code components, supporting the efficient sharing of knowledge among team members or with end-users.

Single-line Comments

Single-line comments are concise and are typically used to give brief explanations or notes within the code. In Java, they are indicated by two forward slashes, `//`. Anything following these slashes on the same line is considered a comment and is ignored by the compiler.

Single-line comments are ideal for quick explanations or to outline the purpose of specific lines of code. They help improve code readability without cluttering the code itself. For example, a single-line comment might explain the purpose of a particular variable or a single line of logic. Using these comments effectively can assist in debugging or when returning to the code after some time.

• Starts with `//`
• Does not affect code execution
• Improves short-term readability
• Great for quick notes

Multi-line Comments

Multi-line comments extend over several lines and are used for longer explanations or for commenting out large blocks of code temporarily. In Java, these comments begin with `/*` and end with `*/`.

This type of comment is helpful when you need to explain more complex logic that cannot be adequately described with a single line or to prevent a block of code from executing without deleting it. Multi-line comments are excellent for providing detailed information about algorithms or complex logical flows.

While they provide a much-needed depth, it’s key to use them judiciously to avoid overwhelming the reader with too much text. Thus, they should be reserved for sections of code where a brief comment isn't sufficient to convey the necessary understanding.

• Enclosed by `/*` and `*/`
• Spans multiple lines
• Useful for larger explanations
• Can be used to temporarily disable code