• Skip to main content
  • Skip to primary sidebar
  • Skip to secondary sidebar
  • Skip to footer

Computer Notes

Library
    • Computer Fundamental
    • Computer Memory
    • DBMS Tutorial
    • Operating System
    • Computer Networking
    • C Programming
    • C++ Programming
    • Java Programming
    • C# Programming
    • SQL Tutorial
    • Management Tutorial
    • Computer Graphics
    • Compiler Design
    • Style Sheet
    • JavaScript Tutorial
    • Html Tutorial
    • Wordpress Tutorial
    • Python Tutorial
    • PHP Tutorial
    • JSP Tutorial
    • AngularJS Tutorial
    • Data Structures
    • E Commerce Tutorial
    • Visual Basic
    • Structs2 Tutorial
    • Digital Electronics
    • Internet Terms
    • Servlet Tutorial
    • Software Engineering
    • Interviews Questions
    • Basic Terms
    • Troubleshooting
Menu

Header Right

Home » Java » Language » What are Comments in Java? – Definition
Next →
← Prev

What are Comments in Java? – Definition

By Dinesh Thakur

When you create new projects, you should see that there is quite a lot of text that is greyed-out and contains slashes and asterisks. These are called comments and,  when you run your program, the compiler will ignore them. Comments are usually non executable statements which are meant for the programmers own convenience.

A comment is usually an explanation regarding the statement. Programmers use comments to allow readers of their code to understand better the code and how it works. Comments consist of English phrases that describe the purpose of the program, the use of identifiers, and the purpose of each program step. It also makes it easier to see where an error might show up. 

Comments in Java are specified in one of three ways. The first two formats are borrowed directly from C++ and C. Comments in Java, as in C++ and C, do not end up in the executable bytecode. For this reason, comments can be used as often as deemed necessary, without the worry of inflated code.

There are three types of comments in java. They are:

We’ll be covering the following topics in this tutorial:

  • Single line (or end-of line) comment
  • Multi line comment
  • Documentation comment

Single line (or end-of line) comment

Single line comment allows only one line. It starts with a double slash symbol (//) and terminates at the end of the current line. The compiler ignores everything from // to the end of the line. For example:
// Calculate sum of two numbers

Multi line comment

If the comment exceeds more than one line, multiline comment is used. Java programmer can use C/C++ comment style that begins with delimiter /* and ends with */. All the text written between the delimiter is ignored by the compiler. This style of comments can be used on part of a line, a whole line or more commonly to define multi-line comment. For example.
/* Calculate
sum of two numbers */

Documentation comment

Documentation comment is used to generate document automatically. This comment style is new in Java. Such comments begin with delimiter /** and end with */ . The compiler also ignores this type of comments just like it ignores comments that use /* and */.The main purpose of this type of comment is to automatically generate program documentation. The javadoc tool reads these comments and uses them to prepare your program’s documentation in HTML format. For example. /**The text enclosed here will be part of program documentation */.

A quick note about comments – keep them as short as possible and make sure they are clear on what is happening in the code; long, rambling comments that are full of unnecessary words are meaningless and make your code look even messier. 

You’ll also like:

  1. JavaScript Comments
  2. Comments in C++
  3. How many Types of Comments are there in PHP
  4. What is an identifiers in Java? – Definition
  5. What is Java keyword (reserved words)? – Definition
Next →
← Prev
Like/Subscribe us for latest updates     

About Dinesh Thakur
Dinesh ThakurDinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular Computer Notes blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps.

Dinesh Thakur is a Freelance Writer who helps different clients from all over the globe. Dinesh has written over 500+ blogs, 30+ eBooks, and 10000+ Posts for all types of clients.


For any type of query or something that you think is missing, please feel free to Contact us.


Primary Sidebar

Java Tutorials

Java Tutorials

  • Java - Home
  • Java - IDE
  • Java - Features
  • Java - History
  • Java - this Keyword
  • Java - Tokens
  • Java - Jump Statements
  • Java - Control Statements
  • Java - Literals
  • Java - Data Types
  • Java - Type Casting
  • Java - Constant
  • Java - Differences
  • Java - Keyword
  • Java - Static Keyword
  • Java - Variable Scope
  • Java - Identifiers
  • Java - Nested For Loop
  • Java - Vector
  • Java - Type Conversion Vs Casting
  • Java - Access Protection
  • Java - Implicit Type Conversion
  • Java - Type Casting
  • Java - Call by Value Vs Reference
  • Java - Collections
  • Java - Garbage Collection
  • Java - Scanner Class
  • Java - this Keyword
  • Java - Final Keyword
  • Java - Access Modifiers
  • Java - Design Patterns in Java

OOPS Concepts

  • Java - OOPS Concepts
  • Java - Characteristics of OOP
  • Java - OOPS Benefits
  • Java - Procedural Vs OOP's
  • Java - Polymorphism
  • Java - Encapsulation
  • Java - Multithreading
  • Java - Serialization

Java Operator & Types

  • Java - Operator
  • Java - Logical Operators
  • Java - Conditional Operator
  • Java - Assignment Operator
  • Java - Shift Operators
  • Java - Bitwise Complement Operator

Java Constructor & Types

  • Java - Constructor
  • Java - Copy Constructor
  • Java - String Constructors
  • Java - Parameterized Constructor

Java Array

  • Java - Array
  • Java - Accessing Array Elements
  • Java - ArrayList
  • Java - Passing Arrays to Methods
  • Java - Wrapper Class
  • Java - Singleton Class
  • Java - Access Specifiers
  • Java - Substring

Java Inheritance & Interfaces

  • Java - Inheritance
  • Java - Multilevel Inheritance
  • Java - Single Inheritance
  • Java - Abstract Class
  • Java - Abstraction
  • Java - Interfaces
  • Java - Extending Interfaces
  • Java - Method Overriding
  • Java - Method Overloading
  • Java - Super Keyword
  • Java - Multiple Inheritance

Exception Handling Tutorials

  • Java - Exception Handling
  • Java - Exception-Handling Advantages
  • Java - Final, Finally and Finalize

Data Structures

  • Java - Data Structures
  • Java - Bubble Sort

Advance Java

  • Java - Applet Life Cycle
  • Java - Applet Explaination
  • Java - Thread Model
  • Java - RMI Architecture
  • Java - Applet
  • Java - Swing Features
  • Java - Choice and list Control
  • Java - JFrame with Multiple JPanels
  • Java - Java Adapter Classes
  • Java - AWT Vs Swing
  • Java - Checkbox
  • Java - Byte Stream Classes
  • Java - Character Stream Classes
  • Java - Change Color of Applet
  • Java - Passing Parameters
  • Java - Html Applet Tag
  • Java - JComboBox
  • Java - CardLayout
  • Java - Keyboard Events
  • Java - Applet Run From CLI
  • Java - Applet Update Method
  • Java - Applet Display Methods
  • Java - Event Handling
  • Java - Scrollbar
  • Java - JFrame ContentPane Layout
  • Java - Class Rectangle
  • Java - Event Handling Model

Java programs

  • Java - Armstrong Number
  • Java - Program Structure
  • Java - Java Programs Types
  • Java - Font Class
  • Java - repaint()
  • Java - Thread Priority
  • Java - 1D Array
  • Java - 3x3 Matrix
  • Java - drawline()
  • Java - Prime Number Program
  • Java - Copy Data
  • Java - Calculate Area of Rectangle
  • Java - Strong Number Program
  • Java - Swap Elements of an Array
  • Java - Parameterized Constructor
  • Java - ActionListener
  • Java - Print Number
  • Java - Find Average Program
  • Java - Simple and Compound Interest
  • Java - Area of Rectangle
  • Java - Default Constructor Program
  • Java - Single Inheritance Program
  • Java - Array of Objects
  • Java - Passing 2D Array
  • Java - Compute the Bill
  • Java - BufferedReader Example
  • Java - Sum of First N Number
  • Java - Check Number
  • Java - Sum of Two 3x3 Matrices
  • Java - Calculate Circumference
  • Java - Perfect Number Program
  • Java - Factorial Program
  • Java - Reverse a String

Other Links

  • Java - PDF Version

Footer

Basic Course

  • Computer Fundamental
  • Computer Networking
  • Operating System
  • Database System
  • Computer Graphics
  • Management System
  • Software Engineering
  • Digital Electronics
  • Electronic Commerce
  • Compiler Design
  • Troubleshooting

Programming

  • Java Programming
  • Structured Query (SQL)
  • C Programming
  • C++ Programming
  • Visual Basic
  • Data Structures
  • Struts 2
  • Java Servlet
  • C# Programming
  • Basic Terms
  • Interviews

World Wide Web

  • Internet
  • Java Script
  • HTML Language
  • Cascading Style Sheet
  • Java Server Pages
  • Wordpress
  • PHP
  • Python Tutorial
  • AngularJS
  • Troubleshooting

 About Us |  Contact Us |  FAQ

Dinesh Thakur is a Technology Columinist and founder of Computer Notes.

Copyright © 2025. All Rights Reserved.

APPLY FOR ONLINE JOB IN BIGGEST CRYPTO COMPANIES
APPLY NOW