/* AlertMe, by Chris Minnick and Eva Holland A program to alert users that they are using a JavaScript program called AlertMe, which …

JavaScript comments are a way that you can put text into a program that isn’t a string or a statement. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. To create a multi‐line comment, start with /* and end the comment with the exact reverse, */.


to make it more readable.JavaScript comments can also be used to prevent execution, when W3Schools is optimized for learning, testing, and training. Here is an example of a multi‐line comment. testing alternative code.This example uses a single-line comment before each code line:This example uses a single line comment at the end of each line Examples might be simplified to improve reading and basic understanding. This may not sound so great, but the thing that makes comments so important and useful is precisely that they don’t cause JavaScript to do anything at all.Programmers use comments within their code for several reasons:To tell their future selves, and anyone else who works on the program in the future, why they wrote something in the particular way they didTo leave themselves a note telling what they still need to do, or to list improvements that they intend to make at a later dateJavaScript has two different kinds of comments: single‐line and multi‐line. Question: How do I insert comments in JavaScript code? JavaScript comments can be used to explain JavaScript code, and
Example to explain the code:This example uses a multi-line comment (a comment block) to explain the code:Using comments to prevent execution of code is suitable for //document.getElementById("myH").innerHTML = "My First Page"; Let’s take a quick look at the two different types of JavaScript comment syntax.Single-line comments are written with two forward slashes (//):All characters immediately following the // syntax until the end of the line will be ignored by JavaScript.Block comments, sometimes referred to as mutli-line comments, are written with opening tags (/*) and closing tags (*/). While using this site, you agree to have read and accepted our

var x = 5;      // Declare x, give it the value of 5

If you want to comment more than one line using this then you need to put this on each line.

Any text between // and the end of the line will be ignored by JavaScript (will not be executed). Answer: JavaScript supports three different types of comments: Multiple-line C-style comments.

Everything between /* and */ is a comment, for example: /* This is a comment */ /* C-style comments can span as …

This example uses a single-line comment before each code line:

code testing.This example uses // to prevent execution of one of the code lines:This example uses a comment block to prevent execution of Single line comments start with //. multiple lines:If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail: