Swift 'if let' statement equivalent in Kotlin

Question

In Kotlin is there an equivalent to the Swift code below?

if let a = b.val {

} else {

}

Answer 1

there are two answers above, both got a lot acceptances:

1. str?.let{ } ?: run { }
2. str?.also{ } ?: run { }

Both seem to work in most of the usages, but #1 would fail in the following test:

#2 seems better.