Kotlin Starter Pack

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Collections

It's important to understand that Kotlin's collection are built on top of the Java API. That means a lot for interoperability.

But, Kotlin brings consistency and simplicity.

List of ...

Set of ...

Map to ...

Note that beyond that simplicity, Kotlin provides some cool features, essentially based on extensions of the Java API.

Here a sample of what Kotlin is capable of. You may find more into the Kotlin documentation.

// {
fun main(args: Array<String>) {
//}
  val numbers = listOf(1, 2, 3)
  // forearch with indexes
  numbers.forEachIndexed { index, it -> println("At index $index there is $it") }
  // first()
  println("numbers' first is: ${numbers.first()}")
  // last
  println("numbers' last is: ${numbers.last()}")
  // sum
  println("numbers' sum is: ${numbers.sum()}")
  // etc.
// {
}
//}

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8/10 Collections

Collections

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