• Agreed overall, you will still be competent switching from one language to another, but intricacies and nuance matter a lot here. You may have enough knowledge to solve problems, but will you have enough knowledge to avoid creating new ones too? Like performance issues, or memory leaks, or other unwanted behavior? C++ is a great example here: someone that’s smart but inexperienced might just be dangerous enough to start writing classes with dumb pointers without overriding the copy constructors, and this is just a recipe for disaster.

    I think it would take more than a few months to develop the kinds of experience that you need to be aware of these issues and avoid them. And while C++ is a very easy example to point out here, pretty much all languages have their share of footguns to be aware of, and it just takes time to learn them. A “deep knowledge” of a language is not just about being faster and more productive; it’s also about not creating more issues than the ones your solving.

    • I think the degree of footgun danger depends a lot on the language and the application. I agree that C and C++ are dangerous until you really know what you’re doing, though IMO most of the danger comes down to memory management and that’s a portable skill, once you’ve learned it. That being said, I don’t have a lot of experience with C++. C was my first language so I’m used to plain old normal boring pointers (are those “dumb pointers”?) and I’ve never understood why C++ needs 9 billion types of pointers.

      Go has one particular footgun - loop range variables. Other than that, IMO high-level, garbage collected languages don’t have major footguns like that. My first job was writing a bespoke inventory system for a manufacturing company, and I wrote it in a language I’d never used before - C#. In five years the only major issue that had was due to my inexperience with SQL and had nothing to do with C#. And though I haven’t written nearly as much code, I’d say the same about Java, Ruby, Python, and JavaScript.