Reverse a Number and Calculate the Sum of all Digits in Java

Today, we will see how to reverse a number and calculate the sum of all digits. It is a faster way to reverse a number. Because we will use string in this code. So, let's see how it is.............

import java.util.Scanner;        //import a package to take input from keyboard

public class ReverseNumberByString        //main class
{
    public static void main(String[] args)      //main method
    {
        Scanner input = new Scanner(System.in);        //create an object of type of Scanner



        char []str = new char[50];                  //declare an array of char type

        char[] reverse = new char[50];           //declare an array of char type

        System.out.print("Enter a number to reverse : ");     //user is asked to give an input
        String num = input.next();                 //store the input into a variable type of String

        int i=0, len=num.length(), sum = 0;            //store the length of the string into len by using length(); method

        while(i < len)
        {
            str[i] = num.charAt(i);    //convert the string into char array by charAt(); method
            i++;
        }
        System.out.println();
        System.out.print("After reversing : ");

        for(int j=len-1,k=0;j>=0;j--,k++)
        {
            reverse[k]=str[j];
            System.out.print(reverse[k]);
            sum+=str[j]-(char)48;              
        }

        System.out.println("\n\nSum of all digits : "+sum);
        System.out.println();
    }
}



save this code and use the name of main class as file name. If you have any problem, feel free to leave a comment.......