小编qua*_*ien的帖子

我正在学习 Kotlin，在教程示例中：

fun main() {
    val a: Int = 100
    val boxedA: Int? = a
    val anotherBoxedA: Int? = a

    val b: Int = 1000
    val boxedB: Int? = b
    val anotherBoxedB: Int? = b

    println(boxedA === anotherBoxedA) // true
    println(boxedB === anotherBoxedB) // false
}

为什么两次比较的结果不同？

这是 Kotlin 中的继承示例。

open class Person() {
    var _name : String = ""
    var _age : Int = 0

    constructor(name: String, age : Int)  : this(){
        _name = name
        _age = age
    }
}

class Student() : Person() {
    var _university : String = ""

    constructor (name : String, age: Int, university: String) : super(name, age){
        _university = university
    } 
}

fun main() {
   var person = Person("a", 10)
   var student = Student("b", 18, "MIT")
   println("${person._name} : ${person._age}")
   println("${student._university}")
} …