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Kotlin program to find sum of natural numbers from 1 to N using recursion

Kotlin | Sum of the natural numbers: Here, we are going to learn how to find the sum of the natural numbers from 1 to N (given number) using recursion in Kotlin programming language? Submitted by IncludeHelp, on April 27, 2020

Kotlin - Find sum of natural numbers from 1 to N using recursion

Given a number (num), we have to find the sum of the natural numbers from 1 to num.

Example:

Input:
num = 5

Output:
1+2+3+4+5 = 15

Program to find sum of natural numbers from 1 to N using recursion in Kotlin

package com.includehelp.basic

import java.util.*

//function to calculate sum of natural number using recursion
fun addSum(number:Int):Int{
    return if (number > 0) number + addSum(number - 1) else 0
}

//Main Function entry Point of Program
fun main(args: Array<String>) {
    //Input Stream
    val scanner = Scanner(System.`in`)

    //input integer number
    print("Enter Number  : ")
    val num: Int = scanner.nextInt()

    //Call function to find out sum of all numbers up to given number
    var sum= addSum(num)

    //Print Sum
    println("Sum of All Natural Numbers up to num are : $sum")
}

Output

Run 1:
Enter Number  : 99
Sum of All Natural Numbers up to 99 are : 4950
---
Run 2:
Enter Number  : 999
Sum of All Natural Numbers up to 999 are : 499500