demo5.kt

package my.demo

import kotlin.text.*

fun main(args: Array<String>) { 
  for (arg in args) {
    println(arg)
  }

  data class User(val name: String, val age: Int) {
    override fun equals(other: Any?): Boolean {
      return other is User && other.age == this.age
    }
  }

  val user = User("John", 30)
  val user2 = User("John", 30)
  val user3 = User("John", 40)

  println(user == user2)
  println(user == user3)

  println(user)
  println(user.hashCode())
  println(user2.hashCode())
  println(user3.hashCode())
  println(user.hashCode() == user2.hashCode())

  println(user == user.copy())
  println(user == user.copy(age = 40))
  val copyofwhat = user.copy(age = 100)
  println(copyofwhat.age)

  println(user.component1())
  println(user.component2())

  // create a function that print a user (Github Copilot)
  fun printUser(user: User) {
    println("${user.name} is ${user.age} years old")
  }

  printUser(user)
}

// RESULT below in the terminal
/**************

➜  kotlin cat run
#!/usr/bin/env zsh
kotlinc $1 -include-runtime -d demo.jar && java -jar demo.jar $@ 
➜  kotlin ./run demo5.kt
demo5.kt
true
false
User(name=John, age=30)
71750739
71750739
71750749
true
true
false
100
John
30
John is 30 years old
➜  kotlin yaya!!

************/