Kotlin作用域函数

class DemoScope {
}
fun customPrint(s: String) {
    print(s.uppercase())
}


fun printNonNull(str:String?)
{
    println("Print $str")

    str?.let{
        print("*")
        customPrint(it)
        println()
    }
}
fun printIfBothNonNull(strOne:String?,strTwo:String?)
{
    strOne?.let{ firstString->
        strTwo?.let{
            secondString -> customPrint("$firstString : $secondString")
            println()
        }
    }

}

fun getNullableLength(ns:String?)
{
    println("for $ns")
    ns?.run{
        println("\t is empty?"+isEmpty())
        println("\tlength = $length")
        length

    }
}
class Configuration(var host:String,var port:Int)
class Cat()
{
    var name="Mimi"
    var age=12
    var about="aaaa"
}
data class Person1(var name:String,var age:Int,var about:String)
{
    constructor():this("",0,"")
}
fun writeCteationLog(p:Person1)
{
    println("A new person ${p.name} was created.")
}
fun main()
{
    val jake = Person1("Jake",45,"Android").also {
        writeCteationLog(it)
    }

//    val jake = Cat()
//    val stringDescription = jake.apply {
//        name = "Jake"
//        age = 30
//        about = "Android developer"
//
//    }.toString()
//    println(stringDescription)
//    val configuration = Configuration(host="127.0.0.1", port = 9000)
//    with(configuration)
//    {
//        println("$host:$port")
//    }
//    getNullableLength(null)
//    getNullableLength("")
//    getNullableLength("some string with Kotlin")
//    printIfBothNonNull("First","Second")
//    printNonNull(null)
//    println("$empty")
//    val empty = "test".let{
//        customPrint(it)
//        it.isEmpty()
//    }
}