class KotlinTest{
    val listOfStr = arrayListOf("1", 2, 3)

    fun main() {
        println(listOfStr)
    }
}

fun getNameLength(name: String?): Int {
    return name?.length?: -1
}

val lambda1 = { println("这是个最简单的lambda") }

fun main() {
    println(getNameLength(null))
}