10 Most Common Coding Mistakes

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10 Most Common Coding Mistakes


If you’re learning to code or have been coding for a while, chances are you’ve made some mistakes along the way. Coding is full of pitfalls that novices can easily fall into without realizing it. As they say: “An ounce of prevention is worth a pound of cure.” In this article, I’ll share with you my top 10 most common mistakes that web developers make and the best practices to avoid them.

Not using a code editor.

An IDE or just an editor?

An IDE (integrated development environment) is used to write code and compile it, while an editor only helps you format and edit the code. You can use a text editor like Notepad or Gedit to write your code, but that won’t be very fun. An IDE is better because it lets you:

  • Write faster with shortcuts and auto-complete.
  • Write more accurately because there are no syntax errors.
  • Write more efficiently by using hotkeys instead of manually navigating through menus or clicking buttons in a GUI (graphical user interface). It also runs at near-native speed on its own operating system, so there’s no need for virtualization software that slows down your system performance.

Using the incorrect code.

You might have used a tag instead of a . You might have forgotten to close your tags, or you could have accidentally added an extra slash to the beginning of your selector. All of these are common mistakes that can lead to bugs in your code that may be hard to track down. It’s important to always use the most up-to-date version of each language whenever possible—that means using the newest CSS stylesheets, JavaScript libraries and HTML standards.

Misusing indentation.

Indentation is one of the most important aspects of coding, but it’s often overlooked. There are two types of indentation: tabs and spaces. In HTML, CSS and JavaScript, use four spaces per level instead of tabs because browsers will interpret them as multiple spaces if they aren’t properly indented. This can cause problems with alignment when it comes to code output on a page.

In Python, Java and PHP—which require you to use curly braces around blocks—indenting is even more important than in other languages because the curly braces define where blocks start and end (elements inside one block are only accessible within that same block). You can’t just put any old code inside those braces without having proper indentation because it will make no sense at all. Indentation in these languages is also used to indicate where loops begin and end; you’ll need different levels of indentation depending on how many times you want something repeated over itself until there’s no room left for another loop!

Not using versions of HTML, CSS and JavaScript that work with the most common browsers.

Not using versions of HTML, CSS and JavaScript that work with the most common browsers.

This is a mistake that can lead to a lot of frustration for front-end developers.

Using older web standards will make sure you miss out on some important features like rounded corners and animations in your website, or an app will not function properly because it needs a newer version of HTML than what you used on your site.

Missing a closing tag.

You’ve undoubtedly heard the term “closing tag” before, but what does it mean? A closing tag is simply an HTML element that has a matching opening tag. For example, if you had a paragraph of text that looked like this:

This is some text in my paragraph.

You would need to add another element with the opening tag and close it with a matching closing tag . That way, your browser knows when one section ends and another begins. If you leave off either one of these tags, though—even if the rest of your code is perfect—your browser may not know what to do with all those pieces of text in between them! What happens then? In most cases, browsers will ignore any content between unclosed elements like these. So if we had written our paragraph above without closing tags (for example: Thisis(or something like this),), there would likely be no issue because all those spaces are ignored by most browsers. However if we put some important information directly after our second line break like so…This is some text in my paragraph., then this might cause problems for users who view our code on screen or print out a copy of it later on!

Leaving out the Doctype.

  • The doctype is the first line of a document, and it’s incredibly important. It tells the browser how to interpret the document, and it also determines what kind of standards-compliant rendering will be used to display the content. If you don’t include one in your HTML, you’ll get unexpected results when rendering on different devices (iPad vs. desktop).
  • The code for a doctype is simply: .

Using a CMS without learning HTML first.

If you haven’t learned HTML, don’t use a CMS.

That might sound like I’m trying to discourage people from using one of the most popular tools in web development. But really, it makes sense: if you want to customize your site and make changes to it—which is likely if you’re starting out with your first website—you have to be able to edit the code behind it. And when we talk about “editing” code, we mean adding or removing things from it—not just rearranging things that already exist.

So why would anyone want their website in text format instead of an easy-to-use CMS? Well, some experienced developers might prefer working this way because they figure out faster (and thus save money) than if they were using a drag-and-drop editor for something simple like changing the font size on their site’s logo or header image every time they wanted something new done up front without having any prior knowledge of how those pieces work together as part of an entire system; but writing code can get tiring after awhile too! And even though many people find comfort in knowing exactly what needs done when something goes wrong while others may feel more confident going through each step needed after seeing how someone else solved theirs before them–the truth is always somewhere in between these two extremes.”

Having a bad workflow.

Good workflow is crucial. A bad workflow can lead to a lot of problems, including project delays and even failure. The best way to avoid this is by being aware of what you’re doing and how it will affect your work—but if you’ve already made some mistakes, here are some tips for improving your workflow:

Not using comments.

Comments are an important part of any code. They help you understand the logic behind the code and can also be used to provide instructions for other developers working on your project.

When should you use comments? Anyplace where there’s a section of code that isn’t complete, such as a function that requires additional parameters, or any place where a developer would need further explanation about what the piece of code is doing. This can be especially helpful if someone else has to look at your work later on!

Using inefficient coding methods instead of better alternatives that are available in modern (and older) versions of HTML and CSS.

You may be using a version of HTML or CSS that’s outdated and inefficient. If you’re still using older versions of HTML and CSS, you can use new tags to make your code more efficient. For example, HTML5 has some great tags for creating tables that are easier to read and understand than previous versions.

If you’re using a newer version of HTML (and most browsers will automatically update the coding if they detect an outdated one), then it’s time to check out these best practices:

These coding mistakes can be avoided with practice and patience

These coding mistakes can be avoided with practice and patience.

  • Learning to code is like learning anything else: it takes time, energy, and focus.
  • You will have good days and bad days when you’re coding, but if you persevere through the rough patches then sooner or later your skills will improve.
  • It’s important to use good versions of HTML, CSS, JavaScript and other tools that help you write clean code (like an editor).


These are the top ten coding mistakes that you should avoid. If you’re new to coding and aren’t sure what you should be doing to learn, try taking a free online course or two. They’ll help get you started on the right foot!

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