Kotlin Video Series – Range

This is the tenth part of the video series on Kotlin language.
Read and watch the other parts here.

We discuss range operators in Kotlin language.

The examples used in the video are given below

fun main(args:Array<String>){
   val range = 1 .. 10
   println(range.javaClass)//IntRange
	
   val rangeWithStep = 1 .. 10 step 2
   println(rangeWithStep.first)
   println(rangeWithStep.last)
   println(rangeWithStep.step)
	
   val range2 = 1 until 10
   val range3 = 10 downTo 1 step 2
   println(range3.first)
   println(range3.last)
}

range can be declared using .. operator or using until and downTo keywords with an option incremental step. In the example above range is an instance of IntRange class. So, we can use properties like first, last, step etc., We can also use methods like min(), max(), average(), filter(), map(), reduce() etc.,

  fun print(message:String){
     val range = 1 .. 10
     println(range.max())
     println(range.min())
     println(range.average())
	
     println(range.filter { num -> num % 2 == 0 })
     println(range.map { num -> num * num })
     println(range.reduce { total, num -> total + num })
  }

You can find the video here.