variableDemo.kt

fun main() {
    val variable1 = 10
    println(variable1)
    //variable1 = 20 //Illegal Expression because val can not be reassigned
    var variable2 = 20
    println(variable2)
    variable2 = 30
    println(variable2)
    //printNum(null) // Illegal Expression because variable a is not nullable
    printNum(20)
    printNullNum(null)
}




fun printNum(a: Int){
    println(a)
}
// Notice the question mark after Int which represents that vara is nullable
fun printNullNum(vara: Int?){
    println(vara)
}