[Youtube DiMo] 16강. Object

[16강] https://youtu.be/QPqzmKu0Y_k

 

1. object (소문자/클래스 아님)

object = Singleton Patton 또는 Static Var에 해당

fun main() {
    println(myObj.score)
    myObj.plus(10)
    println(myObj.score)
}

object myObj{
    var score = 0
    fun plus(x : Int) { score += x }
}

0
10

 

 

2. companion object

fun main() {
    var a = menu("짜장")
    var b = menu("짬뽕")
    
    a.vote()
    a.vote()
    a.vote()
    
    b.vote()
    b.vote()
    
    println("${a.name} : ${a.count}")
    println("${b.name} : ${b.count}")
    println("총계 : ${menu.total}")
}

class menu(val name : String) {
    companion object {
        var total = 0
    }
    
    var count = 0
    
    fun vote() {
        count++
        total++
    }
}

짜장 : 3
짬뽕 : 2
총계 : 5