My ZSH shell outputs helloworld for both of the above examples. However, my custom shell, which is passing all of the single and double quote tests, outputs hello’'world and hello""world respectively.
Hey, if you are on the echo builtin stage (#iz3), then ignore this for now, as quotes are handled in the quoting extension.
If you are not, it still causes an error in my program using the command echo hello’'world. I found out after seeing your comment, so i just wrote some exception code to handle this, but the project itself does not provide any case in this specific scenario.