JavaScript for Beginners: JavaScript Issues
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- JavaScript for Beginners
- Programming Tips
- It might not be there
- Not all browsers have JavaScript. Some non-visual browsers won’t use it. And you cannot rely on JavaScript existing even in visual browsers. Even if the viewer leaves JavaScript turned on in their browser, there’s a very good chance that some functionality will be turned off. Mostly, this is because JavaScript is commonly abused by scammers.
- Trusting JavaScript
- You cannot trust JavaScript at all. Not only can the viewer turn JavaScript off, but they can also change it. A JavaScript file is just like a web page: it gets downloaded to the client computer and then “displayed”. The viewer has full control over the file since it is on their computer, and malicious scripters can take advantage of this if you trust the “output” of JavaScript.
- Different Versions
- Different web browsers, and different versions of web browsers, will often treat the same JavaScript slightly differently. This will be more of an issue the more complex your JavaScript becomes. Try to keep your JavaScript standard, try to test on a wide variety of browsers and versions, and make sure your web pages work if your viewers end up having to turn JavaScript off to bypass inadvertent bugs in your JavaScript. Remember that just because…
- Managing Your Script Files
- If you look at other people’s web pages, you’ll notice that sometimes they’ll put JavaScript right inside their web pages, instead of putting it into a separate file as we’ve done here. I recommend against this. By putting your JavaScript into a separate JavaScript (.js) file, you can call the same file from different web pages. If a new browser version necessitates changing your JavaScript code to overcome a new bug, you’ll be able to make the…
