- JavaScript Basics
- JavaScript Home
- JavaScript Syntax
- JavaScript Placements
- JavaScript Output
- JavaScript Statements
- JavaScript Keywords
- JavaScript Comments
- JavaScript Variables
- JavaScript var
- JavaScript let
- JavaScript const
- JavaScript var Vs let Vs const
- JavaScript Operators
- JavaScript Arithmetic Operators
- JavaScript Assignment Operators
- JS Comparison Operators
- JavaScript Logical Operators
- JavaScript Bitwise Operators
- JavaScript Ternary Operator
- JavaScript Operator Precedence
- JavaScript Data Types
- JavaScript typeof Operator
- JS Conditional Statements
- JavaScript Conditional Statement
- JavaScript if Statement
- JavaScript if-else Statement
- JavaScript switch Statement
- JavaScript Loops
- JavaScript for Loop
- JavaScript while Loop
- JavaScript do-while Loop
- JavaScript Break Continue
- JavaScript Popup Boxes
- JavaScript Dialog Box
- JavaScript alert Box
- JavaScript confirm Box
- JavaScript prompt Box
- JavaScript Functions
- JavaScript Functions
- JS Function with Parameter
- JavaScript Return Statement
- JavaScript Variable Scope
- JavaScript setTimeout() Method
- JavaScript setInterval() Method
- JavaScript Events
- JavaScript Events
- JavaScript onclick Event
- JavaScript onload Event
- JavaScript Mouse Events
- JavaScript onreset Event
- JavaScript onsubmit Event
- JavaScript Objects
- JavaScript Objects
- JavaScript Number Object
- JavaScript Array Object
- JavaScript String Object
- JavaScript Boolean Object
- JavaScript Math Object
- JavaScript RegExp Object
- JavaScript Date Object
- JavaScript Browser Objects
- JavaScript Browser Objects
- JavaScript Window Object
- JavaScript Navigator Object
- JavaScript History Object
- JavaScript Screen Object
- JavaScript Location Object
- JavaScript Document Object
- JS Document Object Collection
- JS Document Object Properties
- JS Document Object Methods
- JS Document Object with Forms
- JavaScript DOM
- JavaScript DOM
- JavaScript DOM Nodes
- JavaScript DOM Levels
- JavaScript DOM Interfaces
- JavaScript Cookies
- JavaScript Cookies
- JavaScript Create/Delete Cookies
- JavaScript Advance
- JavaScript Regular Expression
- JavaScript Page Redirection
- JavaScript Form Validation
- JavaScript Validations
- JavaScript Error Handling
- JavaScript Exception Handling
- JavaScript try-catch throw finally
- JavaScript onerror Event
- JavaScript Multimedia
- JavaScript Animation
- JavaScript Image Map
- JavaScript Debugging
- JavaScript Browser Detection
- JavaScript Security
- JavaScript Misc
- JavaScript innerHTML
- JavaScript getElementById()
- JS getElementsByClassName()
- JS getElementsByName()
- JS getElementsByTagName()
- JavaScript querySelector()
- JavaScript querySelectorAll()
- JavaScript document.write()
- JavaScript console.log()
- JavaScript instanceof
- JavaScript Programs
- JavaScript Programs
- JavaScript Test
- JavaScript Online Test
- Give Online Test
- All Test List
JavaScript Comments
The word comment refers to a written remark or opinion about any thing. And in computer programming world, a comment is a piece of text placed within a program, that helps other programmer to understand the program.
The comments are ignored while executing the program. Therefore, comments are often helpful while debugging the code.
You can use comment for multiple purposes. For example, use comment to:
- explain some block of code
- explain particular statement
- avoid executing some statement or block of code
- debug the code
- etc.
Types of Comments in JavaScript
There are two types of comments, JavaScript allows. That are:
- Single line comment
- Multi-line comment
Single Line Comment in JavaScript
A single line comment in JavaScript, starts with //. That is, anything written after the // on the same line, will be treated as a comment. For example:
<!DOCTYPE html> <html> <body> <script> document.write("One"); // document.write("Two"); document.write("Three"); // document.write("Four"); document.write("Five"); </script> </body> </html>
Multi-line Comment in JavaScript
Multi-line comment in JavaScript, starts with /* and ends with */. That is, anything between /* and */ will be treated as a comment. For example:
<!DOCTYPE html> <html> <body> <script> document.write("One"); /* document.write("Two"); document.write("Three"); */ document.write("Four"); /* document.write("Five"); */ document.write("Six"); /* document.write("Seven"); document.write("Eight"); */ document.write("Nine"); </script> </body> </html>
« Previous Tutorial Next Tutorial »