编辑代码

package com.oracle

fun testlet(arg: String?): Int {
    arg?.let {
        var contentLen = 1
        if(arg.equals("hehe")) {
            contentLen = 100
        } else {
            println("NOT equals!")
        }
        println("tesetlet: len: $contentLen")
        return if(contentLen==100){11} else {2}
    }
    return 0

}

class Book {
    var name = "《数据结构》"
    var price = 60
    fun displayInfo() = println("Book name : $name and price : $price")
}

fun main(args: Array<String>) {
    println(testlet("hehe1"))
    println("-----------")
    //println(book)
    val book2 = Book()
    book2.name="tt"
    book2.price = 77
    book2.displayInfo()

    val book = Book().let {
        it.name = "《计算机网络》"
        it.price = 10
        println("book test...")
    
    }
    //book.displayInfo()

    //println("result: ${book.name}")
}