JavaScript comments are used to explain the code to make it more readable. It can be used to prevent the execution of a section of code if necessary. JavaScript comments are ignored while the compiler executes the code.
A single-line comment in JavaScript is denoted by two forward slashes (//
),
Syntax:
// your comment here
Example 1: This example illustrates the single-line comment.
Javascript
console.log( "Hello Geeks!" );
|
Example 2: In this example, we will assign values to some variables and explain them with single-line comments.
Javascript
let geek = 'Computer science portal' ;
console.log(geek)
let sum = 5 + 8
console.log(sum)
|
Output
Computer science portal
13
A multiline comment in JavaScript is a way to include comments that span multiple lines in the source code.
Syntax:
/*
This is a multiline comment
It can span multiple lines
*/
Example: This example illustrates the multi-line comment using /* … */
Javascript
console.log( "Multiline comment in javascript" );
|
Output
Multiline comment in javascript
JavaScript Comments to Prevent Execution
We can use // or /*…*/ to change the JavaScript code execution using comments. JavaScript Comments are used to prevent code execution and are considered suitable for testing the code.
Example 1: JavaScript comments are used to prevent execution of selected code to locate problems of code or while testing new features. This example illustrates that commented code will never execute.
Javascript
function add() {
let x = 10;
let y = 20;
let z = x + y;
console.log(z);
}
add();
|
Example 2: This example uses multi-line comments to prevent the execution of addition code and perform subtraction operations.
Javascript
function sub() {
let x = 10;
let y = 20;
let z = x - y;
console.log(z);
}
sub();
|
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Last Updated :
08 Dec, 2023
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