Java Comments
Java Comments
Comments in Java are notes written inside the code to explain what the program or a particular line does. Comments make code more readable and help programmers understand logic easily — especially when coming back to code later.
Comments are ignored by the Java compiler and do not affect the program output.
Types of Comment in Java
Java supports three types of comment:
| Type | Format | Usage |
|---|---|---|
| Single-line comment | // comment | Short explanations |
| Multi-line comment | /* comment */ | Longer explanations or block comments |
| Documentation (JavaDoc) comment | /** comment */ | Generate API documentation |
Single-Line Comment
Used to comment one line or short notes.
Example:
Multi-Line Comment
Used when explanation spans multiple lines.
Documentation Comment (JavaDoc)
Used to describe classes, methods, and generate HTML documentation using the javadoc tool.
Why Use Comments?
To explain logic
To describe functions or variables
For debugging (temporarily disable code)
To help other developers understand code
Commenting Out Code (Debugging)
You can disable code temporarily using comments:
Wrong Usage Example
You cannot put a comment in the middle of a statement:
Correct Usage
Example Program With All Comments
Summary
| Comment Type | Symbol | Purpose |
|---|---|---|
| Single-line | // | Small notes |
| Multi-line | /* ... */ | Large explanation or block |
| JavaDoc | /** ... */ | Generate documentation |
