val array = arrayOf(1, 2, 3, 4, 5)
val sum = array.sum()
val first = array.first()
val last = array.last()
val biggest = array.maxOrNull()

var name = "John"
    get() = field.toUpperCase()
    set(value) {
        field = value.toLowerCase()
    }

import java.util.*
fun main(args: Array<String>) {
    val scanner = Scanner(System.`in`)
    print("Enter your name: ")
    val name = scanner.nextLine()
    println("Name is: $name")
    scanner.close()
}

val name = "John"
println("Hello, $name")

val name: String? = null
val length = name?.length ?: -1
println(length ?: "No name")

data class Person(val name: String, val age: Int)
val John = Person("John", 30)
val anotherJohn = Person("John", 30)
println(John.equals(anotherJohn))

fun sayHi(name: String = "No one", age: Integer) = println("Hi, $name, you are $age years old")
sayHi(age = 30)

println(5 in 1..10)
for(i in 1..10) {
    println(i)
}

data class Point(val x: Int, val y: Int)

operator fun Point.unaryMinus() = Point(-x, -y)

val point = Point(10, 20)

fun main() {
   println(-point)  // prints "Point(x=-10, y=-20)"
}

infix fun Int.powerOf(n: Int): Int {
    return this.pow(n)
}
println(2 powerOf 3)

fun MutableList<Int>.swap(index1: Int, index2: Int) {
    val tmp = this[index1] // 'this' corresponds to the list
    this[index1] = this[index2]
    this[index2] = tmp
}
val list = mutableListOf(1, 2, 3)
list.swap(0, 2) // 'this' inside 'swap()' will hold the value of 'list'

val person = object {
    val name = "John"
    val age = 30
}
println(person.name)

data class Person(val name: String, val age: Int)
val (name, age) = Person("John", 30)

data class Person(var name: String, var age: Int = 0, var city: String = "")
val adam = Person("Adam").apply {
    age = 32
    city = "London"        
}
println(adam) // Person(name=Adam, age=32, city=London)

fun getStringLength(obj: Any): Int? {
    if (obj is String) {
        return obj.length
    }
    return null
}