Why This CTO Thinks JavaScript Is the Worst Programming Language

The other day, I was chatting with a friend about programming languages, and—of course—JavaScript came up. We've worked with JavaScript for a while, so we're no strangers to its quirks. But it’s not just us. Many tech leaders have voiced their frustrations with this language over the years.

As a CTO, I generally don’t recommend JavaScript as someone’s first—or only—language, especially for beginners.

Sure, JavaScript looks beginner-friendly at first glance. It runs in the browser, you can see results quickly, and there's a huge ecosystem. But as you dig deeper, the flaws start to show. It's easy to learn, but painfully hard to master. Here's why I (and many others) have serious issues with it:

1. Single-threaded by design
   JavaScript uses an event loop to handle asynchronous operations. While clever, this architecture limits performance and scalability in compute-heavy tasks.

2. Automatic type coercion
   You never quite know what you're going to get when performing operations. [] + {} is an empty string, but {} + [] is [object Object]. These inconsistencies introduce bugs you didn’t even know were possible.

3. No native namespaces
   Variables or functions with the same name can be redefined unintentionally. There’s no true namespacing, which makes code organization and maintainability more painful, especially in larger codebases.

4. Implicit global variables
   If you forget to declare a variable with let, const, or var, it automatically becomes global. One typo can ruin your day.

5. The unpredictable nature of arrays
   You never really know whether a number is an integer or a float, and arrays can act in bizarre ways. It's like dating someone who changes personalities without warning.

6. null vs. undefined
   They seem similar but behave differently. Their subtle differences confuse both new and seasoned developers. Honestly, we might have been better off without null altogether.

Final thoughts
I’m not saying JavaScript doesn’t have its place—clearly, it powers a massive portion of the web. But as a CTO, I think it’s crucial to recognize its shortcomings and consider whether it’s the best tool for the job, especially for beginners who are still learning the fundamentals of programming.

What do you think—am I being too harsh? Or do you secretly agree?