


How to hide JavaScript code from older browsers that don't support JavaScript?
Older browsers sometimes don't understand JavaScript script tags. If not, they will only Ignore it and display your script as if it were part of the (X)HTML document body. it is A smart option to use comments to hide scripts in outdated browsers to prevent this from happening.
All modern browsers now support JavaScript; however, early browsers did not. at this In this article, we will learn how to prevent JavaScript code from executing in older browsers.
Because some of your viewers will be viewing the site on mobile phones, while others are using large desktops On the screen, a website cannot look exactly the same in all browsers. Likewise, some of your Users will use outdated browsers while others will use the latest browsers. Some Your users may be using a screen reader to hear your message read aloud, or may have Zoom in to read. Provides a defensive version of content that looks great Modern browsers, but still usable at a basic level for users of older browsers is the concept "Support everyone."
Strategy - We will use single-line HTML comments without a terminator ( 标签已打开。之后,我们将创建隐藏的 JavaScript 代码 来自早期的浏览器。在我们使用结束符之前,脚本将使用 标签结束 带注释的字符 (//->) after them.
grammar
<script> <!-- // Your JavaScript code // that is hidden from older browser console.log("Tutorials Point"); //--> </script>
Example 1
In this example let us understand that if the browser is a browser that supports JavaScript, the background The color will change to red; otherwise, it will remain yellow.
<!DOCTYPE html> <html> <title>How can JavaScript code be hidden from old browsers that do not support JavaScript - TutorialsPoint</title> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> </head> <body bgcolor="green"> <h1 style="text-align: center; font-size: 3rem;"> Learn JavaScript with TutorialsPoint! </h1> <script type="text/javascript"> <!-- document.bgColor = "orange"; //--> </script> </body> </html>
We can observe that outdated browsers ignore JavaScript code and treat it as HTML Note, while current browsers can access JavaScript code without any problem.
Displays orange when the browser supports JavaScript, as added in the style Example above.
Next, when the browser does not support JavaScript, it will be displayed in green, as added in the style the above example.
Example 2
For browsers that support JavaScript, this script hiding method also works. The first sum of the script The last few lines serve as titles. Client-side JavaScript interpreter understands HTML However, treat it like a single-line comment.
Therefore, the second line is treated as a single-line comment in browsers that support JavaScript. similar You can see that the line below starts with a single line comment string twice and therefore supports JavaScript The browser will also skip that line. Now only lines 3 to 5 are still running Executed as a JavaScript statement.
Although it takes some getting used to, this simple and elegant HTML and JavaScript comments achieve our desired goal of preventing JavaScript code from being displayed Browsers that don't support JavaScript. The use of this kind of comment is still very common Although fewer browsers now require it, it exists in JavaScript code across the internet.
<!DOCTYPE html> <html> <title>How can JavaScript code be hidden from old browsers that do not support JavaScript - TutorialsPoint </title> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> </head> <body style="text-align:center"> <h2 id="Visit-TutorialsPoint"> Visit TutorialsPoint! </h2> <div id="result"> </div> <script langauge="JavaScript"> <!-- start an HTML comment to hide the script // Here are the JavaScript statements. // // // close the HTML comment which hides the script --> const date = new Date(); document.getElementById("result").innerHTML = (date); </script> </body> </html>
The above is the detailed content of How to hide JavaScript code from older browsers that don't support JavaScript?. For more information, please follow other related articles on the PHP Chinese website!

The main difference between Python and JavaScript is the type system and application scenarios. 1. Python uses dynamic types, suitable for scientific computing and data analysis. 2. JavaScript adopts weak types and is widely used in front-end and full-stack development. The two have their own advantages in asynchronous programming and performance optimization, and should be decided according to project requirements when choosing.

Whether to choose Python or JavaScript depends on the project type: 1) Choose Python for data science and automation tasks; 2) Choose JavaScript for front-end and full-stack development. Python is favored for its powerful library in data processing and automation, while JavaScript is indispensable for its advantages in web interaction and full-stack development.

Python and JavaScript each have their own advantages, and the choice depends on project needs and personal preferences. 1. Python is easy to learn, with concise syntax, suitable for data science and back-end development, but has a slow execution speed. 2. JavaScript is everywhere in front-end development and has strong asynchronous programming capabilities. Node.js makes it suitable for full-stack development, but the syntax may be complex and error-prone.

JavaScriptisnotbuiltonCorC ;it'saninterpretedlanguagethatrunsonenginesoftenwritteninC .1)JavaScriptwasdesignedasalightweight,interpretedlanguageforwebbrowsers.2)EnginesevolvedfromsimpleinterpreterstoJITcompilers,typicallyinC ,improvingperformance.

JavaScript can be used for front-end and back-end development. The front-end enhances the user experience through DOM operations, and the back-end handles server tasks through Node.js. 1. Front-end example: Change the content of the web page text. 2. Backend example: Create a Node.js server.

Choosing Python or JavaScript should be based on career development, learning curve and ecosystem: 1) Career development: Python is suitable for data science and back-end development, while JavaScript is suitable for front-end and full-stack development. 2) Learning curve: Python syntax is concise and suitable for beginners; JavaScript syntax is flexible. 3) Ecosystem: Python has rich scientific computing libraries, and JavaScript has a powerful front-end framework.

The power of the JavaScript framework lies in simplifying development, improving user experience and application performance. When choosing a framework, consider: 1. Project size and complexity, 2. Team experience, 3. Ecosystem and community support.

Introduction I know you may find it strange, what exactly does JavaScript, C and browser have to do? They seem to be unrelated, but in fact, they play a very important role in modern web development. Today we will discuss the close connection between these three. Through this article, you will learn how JavaScript runs in the browser, the role of C in the browser engine, and how they work together to drive rendering and interaction of web pages. We all know the relationship between JavaScript and browser. JavaScript is the core language of front-end development. It runs directly in the browser, making web pages vivid and interesting. Have you ever wondered why JavaScr


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Dreamweaver Mac version
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
