Kotlin Program:

Example:

import java.util.Scanner
fun main(args: Array<String>) {

    print("Enter 1st number : ")
    val userInput = Scanner(System.`in`)
    var n1:Int = userInput.nextInt()
    print("Enter 2nd number : ")
    var n2:Int =userInput.nextInt()
    var temp:Int

    temp=n1
    n1=n2
    n2=temp
    print("After Swap\n 1st number : $n1 \n 2nd number : $n2")
}

Output:

  Enter 1st number : 7
  Enter 2nd number : 15
  After Swap
  1st number : 15
  2nd number : 7

Here we are using 3rd variable (above code temp)

temp = n1  //Insert 1st variable data into temp variable
n1 = n2  //Insert 2st variable data into 1st variable
n2 = temp  //Finally, Insert temp variable data into 2nd variable