If needs else branch in expression of type Unit

[tieskedh]

If operator in function expression

Hello guys, I have bumped into interesting language feature that I cannot make sense of. In Kotlin we can use expression as function body, e.g. fun foo(x: Int, y: Int) = x + y I tried today write following function: fun log() = if (isError()) logError() surprisingly this function couldn’t be compiled. The reason is following: Error:(128, 39) ‘if’ must have both main and ‘else’ branches if used as an expression Can anyone explain me why if listed above is not legit?