Question

Today I read this line of Java code:

if (results.add(userName));

For me, it is the first if statement I’ve ever seen which does not have a then or else clause. I was surprised that it is not a syntax error.

So is there any use of this kind of if statement at all? That is, an if without then or else clause.

Answer 1

No use. It’s very likely a typo. It’s not a special if statement, however. The ; is a statement, the empty statement, which from the language’s point of view, is equivalent to an empty block {}.