Passing a reference is semantically different from passing by reference (the latter being a functionality of the language); doing the former (behind the scenes) doesn't imply that the language supports the latter (if one wants to be rigorous, not even C supports pass by reference).

The canonical example is a function that swaps the variables passed to a function:

    a, b = 10, 20
    swap_fn(&a, &b)
    a == 20 # true

Since the above are primitive data types (ints), in order to make this work, the language needs to generically support passing the address (reference) of the variables. Java¹/Python² etc. are not able to do this; they copy the value of the variable and send it to the function, which will operate on the copy.

¹=at least, last time I've checked, which was long ago :)

²=funny to think that at least in Python, one can mess with the global register of the variables, and actually accomplish that

I don't believe they're saying the feature doesn't exist or never gets used, but rather it's rarely something that's taught to junior developers, and rarely something you see highlighted as a best practice.

I've been developing for 25+ years in any language you can imagine, and know how to use pass by ref just fine, and know there are situations where it might be the best solution.

But I can't remember the last time I've used pass by ref. It's really just a coding style quirk for me, I find it "ugly" and it breaks my train of thought when reasoning through the flow of code. I certainly don't begrudge anyone who uses it though.

And OP's anecdote about the interview is certainly disheartening. You'd hope the interviewer would at least be open to the idea of learning something new. I've learned countless things from developers I've interviewed over the years, and I was incredibly happy about it each time.

Edit: In re-reading your comment and below replies it seems you may be misunderstanding what's being discussed. Yes, the things we pass into and out of functions tend to be object references by default. But when we say "pass by ref" (in some languages at least) we mean, essentially, modifying a value in a calling function without actually returning anything from the called function. That's a horrible way to explain it, but the MS documents for the "ref" keyword do a good job of showing examples:

https://learn.microsoft.com/en-us/dotnet/csharp/language-ref...

They use pass by value but objects are reference valued.

All those languages pass by value and it's kind of embarrassing that you mixed it up while criticizing someone else for not knowing it.

One necessary (but insufficient) test you can use to determine if your language has call by reference or call by value is whether you can implement a swap function. In the languages you list, a swap function is not possible to implement, whereas in C++ it is, which tells you that those languages do not implement pass by reference.

I'm definitely nitpicking here, but I'd say almost all languages use pass-by-value, and what you're talking about is copying a pointer. C++ actually has true pass by reference, nothing is copied in memory.