Is it valid all the challenges test?

Question

HashSet<String> set = new HashSet<String>();
set.add("p");
set.add("Big");
set.add("@");
set.add("big);
set.add("Dog");
set.add(";;");
system.out print(set.size());

output:5 I don't think

Answer 1

If you think a quiz question is invalid, you can report it. Click back to the challenge screen and view the answers. On each of the quiz answer pages there is a "STOP" sign with an exclamation mark inside it. Click it and describe the reason.