Hashcode generation

hashcode_kotlin.kt

/**
 * You can edit, run, and share this code. 
 * play.kotlinlang.org 
 */

val test1 = "test1"
val test2 = "test2"
val test3 = "test3"
val test4 = null

open class A {
    protected fun Int.lhash(i: Any?) =  31 * this + i.hashCode()
    open fun hashcode(): Int = 31
        .lhash(test1)
      	.lhash(test4)
      	.lhash(test2)
      	.lhash(test3)
}

class B: A(){
    val a = 5
    override fun hashcode():Int {
    	return super.hashcode().lhash(a)
    }
}

fun main() { 
    println("hashCode4=>${A().hashcode()}")   
    println("hashCode4=>${B().hashcode()}")   
}