Write a program to find out the sum of natural numbers using recursion in java

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Hello guys, welcome to Lingarajtechhub.com. Today we are going to discuss about find out the sum of natural numbers using recursion in java.

   package com.recursion.java;
   import java.util.Scanner;

   public class Sum_of_natural_no {

   public static void main(String[] args) {
   int number;
   Scanner Sc=new Scanner(System.in);
   System.out.println("enter number");
    number=Sc.nextInt( );
    System.out.println("sum of natural numbers:"+sum(number));
                }
    public static int sum(int value) {
    if(value==0)
    return 0;
    return value+sum(value-1);
    }
     }

Line-1:

 ❖ Package com.recursion.java;

            It is a java package( com.recursion.java) which is a collection of classes and this package is created in a java project .

Line-2:

❖ import java.util.Scanner;

             Scanner is a class in java. util package used for obtaining the input of the primitive types like int, double, etc. and strings .

Line-4:

❖ public class Sum_of_natural_no {

            *Here  Sum_of_natural_no is defined as a class which is a template used to create objects and to define object data types and methods . >–and it’s defined as public because it can be accessed anywhere .

Line-6:

 ❖ public static void main(String[] args)

             >>– it is a main method in which we can execute a program //public :it is an access modifier of the main function which must be public so that the JVM which is (Java Virtual Machine)can access and execute this method. 

           //If a method is not public, then access is restricted and its showing error //static is a keyword in which main method has must to be static in which JVM can load the class into memory and call the main method without creating an instance

         //void it means no return type

         //main() is function string[]args : string means collection of characters ,String[] args represents a collection of Strings that are separated by a space and can be typed into the program on the terminal directly

Line-7:

 ❖ int number;

        >>– here we declare a number  as a variable which is integer type.

Line-8:

 ❖ Scanner sc=new Scanner(System.in);

          >>–it means here scanner is a class and Sc is the instance of the object which is new Scanner.System.in is an argument 

Line-9:

❖ System.out.println(“Enter the number “);   

          >>– it means System is a class name and out is an instance of the System println is print a new line .

Line-10:

  •  number=sc.nextInt();

         >>– here number  is a variable that we take and Sc is our instance name which is created for an object and nextInt() is a method method of a Scanner object that reads in a string of digits or char and converts them into an int type.

Line-11:

❖ System.out.println(“sum of natural numbers:”+sum(number)); }

        >> >>– it means System is a class name and out is an instance of the System println is print a new line .

        >>>>– + means concatenate or comma operator. 

Line-13:

  • Public static int sum(int value) {

          >>– it is a main method in which we can execute a program //public :it is an access modifier of the main function which must be public so that the JVM which is (Java Virtual Machine)can access and execute this method. 

  //If a method is not public, then access is restricted and its showing error 

  //static is a keyword in which main method has must to be static in which JVM can    load the class into memory and call the main method without creating an instance

  //int  it means  return type.

 //sum it to add all the numbers.

Line-14:

  • if(value==0)

 //if it means we are using a for loop and then the value is double equal to 0.

Line-15:

  • Return 0

  // it means we use int to return some value.

Line-16:

  •   Return value+sum(value-1);

>>it means we use int to return some value in this way.

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SONALIN SAHOO

Myself Sonalin Shaoo. I am quite happy to contribute here some java programming content and my friends Lipsa Mohanty ,Sushil Puhan, Aswin Kumar Nayak also help me to contribute their Opinion on this .

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