/* 9월11일
val data4: Int by lazy{
    println("in lazy......")
    10
}

fun main() {
    println("in main......")
    println(data4 + 10)
    println(data4 + 10)
} 
*/

/*
fun main(){
    val str1 = "Hello \n World"
    val str2 = """
        Hello
        World
    """
    println("str1 : $str1")
    println("str2 : $str2")
}
*/

/*
fun main(){
    fun sum(no: Int): Int{
        var sum = 0
        for (i in 1..no){
            sum += i
        }
        return sum
    }

    val name: String = "kkang"
    println("name : $name, sum : ${sum(10)}, plus : ${10 + 20}")
}
*/

/*9월 18일*/

/* 3-7
fun main (){
    var name: String? = null

    println(name)
    
    name = "홍길동"
    
    println(name)
} */

/* 3-8
fun main(){
    fun some(data1: Int, data2: Int=10): Int{
        return data1 *data2
    }
    println(some(10))
    println(some(10, 20))
} */

/* 3-9
fun main(){
    val data1: Array<Int> = Array(3, { 0 })
    data1[0] = 10
    data1[1] = 20
    data1.set(2, 30)

    println(
        """
        array size : ${data1.size}
        array data : ${data1[0]}, ${data1[1]}, ${data1.get(2)}
        """
    )
} */

/* 3-10
val data1 = intArrayOf(10, 20, 30)
val data2 = booleanArrayOf(true, false, true)

fun main(){
    val data1 = arrayOf<Int>(10, 20, 30)
    println(
        """
        array size: ${data1.size}
        array data : ${data1[0]}, ${data1[1]}, ${data1.get(2)}
        """
    )
} */