Comments in Java - Single-line, Multi-line and Javadoc
⏱️ 5 min read • Beginner Level • Lesson 8
Completed on . You can revise this lesson or continue to the next topic.
Comments in Java are used to explain code, improve readability, and make programs easier to maintain. Comments are ignored by the Java compiler and do not affect program execution.
Types of Comments in Java
Java Supports Three Types of Comments
- Single-line Comment
- Multi-line Comment
- Documentation (Javadoc) Comment
Single-line Comment
Single-line comments are used for short explanations and begin with
//.
// This is a single-line comment
public class Demo {
public static void main(String[] args) {
System.out.println("Hello World"); // prints output
}
}
// on a line is treated as a comment and ignored by the compiler.
Multi-line Comment
Multi-line comments are used for longer explanations and are written between
/* and */.
/*
This is a multi-line comment
It spans multiple lines
*/
public class Example {
public static void main(String[] args) {
System.out.println("Multi-line comment example");
}
}
Documentation Comment (Javadoc)
Documentation comments are used to generate API documentation using the
javadoc tool.
/**
* This class demonstrates documentation comment.
* @author ProwessApps
* @version 1.0
*/
public class Demo {
/**
* Adds two numbers
*/
public int add(int a, int b) {
return a + b;
}
}
/** and are used to create professional API documentation.
- Comments improve code readability.
- Comments do not affect program execution.
- Single-line comments start with
//. - Multi-line comments are enclosed within
/* */. - Javadoc comments help generate documentation.
- Java supports 3 types of comments.
- Single-line comments are used for short notes.
- Multi-line comments are used for detailed explanations.
- Documentation comments help generate API docs.
Interview Questions ⭐
🧠 Test your understanding with a quick quiz
🚀 Quick Knowledge Check
Topic: Comments | Language: Java
Q1. Which symbol is used for single-line comments in Java?
Q2. Which tool processes Java documentation comments?
/** Example comment */Q3. Which type of comment is best for multiple lines in Java?
Q4. Which of the following is a valid documentation comment in Java?
Q5. What happens if comments are placed inside code in Java?
System.out.println(10 /* comment */ + 20);🎉 Great job! Keep learning Java step by step.
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