class Site(val map: MutableMap<String, Any?>) { val name: String by map val url: String by map } fun main(args: Array<String>) { var map:MutableMap<String, Any?> = mutableMapOf( "name" to "W3xue教程", "url" to "www.w3xue.com" ) val site = Site(map) println(site.name) println(site.url) println("--------------") map.put("name", "Google") map.put("url", "www.google.com") println(site.name) println(site.url) }