What ramdon ass language could they possibly be pulling out of their ass for you to he completely unable to write a for loop? I've yet to see a for loop, or really any sort of loop that doesn't look pretty much exactly like the standard C style for loop

for(int x = 0; x < z; x++) {
}

If you have a C style language with iterator for loops like C++, Java and friends you almost certainly have this syntax

for(int x : numbers) {
}

Python has exclusively iterator for loops with this syntax

for x in range(z)

The only real difference is that instead of a colon : you use the in token.

At best I can see the need for a quick refresh on what the exact syntax is but if your a senior any languages you actually use should have a template for junk like this. I don't think I've manually written a loop in ages, I just type out iter for an iterator for loop or when I rarely need an index fori and the rest gets stamped out for me.

If your being tested on random languages you can simply just not be familiar with a language. I haven't touched Zig once but I'd totally be down to learn it. Everybody whos got a couple languages under their belt knows how easy it is to pick up new ones.