also就是*.let ，只不过。这域的返回值是also对象本身。不再是最后一行

fun main(args : Array<String>){
    var v1 = V()
    v1.also{
        it.name = "fd"
    }.t1("hi")
}

class V {
    var name = "fd"
    
    fun t1(v:String){
        println("test1 $v $name")
    }
}