mapNotNull
Returns a list containing only the non-null results of applying the given transform function to each character in the original char sequence.
inline fun <R : Any> CharSequence.mapNotNull(transform: (Char) -> R?): List<R>(source)
fun main() {
val text = "abc123def456"
val digits = text.mapNotNull {
if (it.isDigit()) it.toString().toInt() else null
}
println(digits) // Output: [1, 2, 3, 4, 5, 6]
}