Documentation with Comments

Introduction to Documentation with Comments

• Comments are text within a program that is completely ignored by the compiler.
• Their purpose is to provide explanations, clarifying the functionality of the code to both the original author and other developers.
• They are a critical component of code documentation, one of the best practices of software development.

Types of Comments in Java

• Java supports two types of comments: single-line comments and multi-line comments.
• Single-line comments are preceded by //, which tells the compiler to ignore everything after // on a line.
• Multi-line comments begin with /* and end with */, which instructs the compiler to ignore everything in between, even if it spans multiple lines.

Use of Comments in Code Documentation

• Comments should provide information that’s not immediately clear from the code itself.
• Use them to explain the purpose of a class, method or variable, and how it interacts with other components.
• Do not use them to state the obvious. For example, avoid comments like: i++; // increment i

Example of Documentation with Comments

• Consider a class Circle with one private attribute called radius:

  // Class to represent a circle in a 2D space
  public class Circle {
    private double radius; // radius of the circle in units
  
    public double getRadius() {
        return this.radius; // return the radius of the circle
    }
  }
  

• In the code above, the comments provide clear documentation about the purpose of the Circle class and its components.

Best Practices for Commenting

• Always keep comments succinct and relevant.
• Update comments when code changes to maintain the accuracy of the documentation.
• Use a coding style guide (like Javadoc in Java) to consistently structure comments.

Significance of Comments in Software Development

• Comments help make code more understandable, maintainable, and reusable.
• They allow other developers to understand your design decisions and thought process.
• High-quality comments often lead to fewer bugs and more efficient troubleshooting.