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

To unwrap multiple variables at once like in the Swift if let syntax you may consider a global utility function along the following lines (example takes 3 parameters, but you can define overloads for any number of parameters):

inline fun  notNull(
    a: A?, b: B?, c: C?, perform: (A, B, C) -> Unit = { _, _, _ -> }
): Boolean {
    if (a != null && b != null && c != null) {
        perform(a, b, c)
        return true
    }
    return false
}

Sample usage:

if (notNull("foo", 1, true) { string, int, boolean ->
    print("The three values were not null and are type-safe: $string, $int, $boolean")
}) else {
    print("At least one of the vales was null")
}