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Java Exercises: Compute the sum of the digits of an integer

Java Basic: Exercise-33 with Solution

Write a Java program and compute the sum of the digits of an integer.

Test Data:
Input an intger: 25

Pictorial Presentation:

Java: Compute the sum of the digits of an integer

Sample Solution:

Java Code:

import java.util.Scanner;
public class Exercise33 { 
 public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Input an integer: ");
        long n = input.nextLong();
        System.out.println("The sum of the digits is: " + sumDigits(n));

    }

    public static int sumDigits(long n) {
        int sum = 0;
        while (n != 0) {
            sum += n % 10;
            n /= 10;
        }
        return sum;
    }
}

Sample Output:

Input an intger: 25                                                                                           
The sum of the digits is: 7 

Flowchart:

Flowchart: Java exercises: Compute the sum of the digits of an integer

Java Code Editor:

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Next: Write a Java program to compute the area of a hexagon.

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Java: Tips of the Day

Try and catch:

Java is excellent at catching errors, but it can only recover gracefully if you tell it what to do. The cascading hierarchy of attempting to perform an action in Java starts with try, falls back to catch, and ends with finally. Should the try clause fail, then catch is invoked, and in the end, there's always finally to perform some sensible action regardless of the results. Here's an example:

try {
        cmd = parser.parse(opt, args); 
       
        if(cmd.hasOption("help")) {
                HelpFormatter helper = new HelpFormatter();
                helper.printHelp("Hello ", opt);
                System.exit(0);
                }
        else {
                if(cmd.hasOption("shell") || cmd.hasOption("s")) {
                String target = cmd.getOptionValue("tgt");
                } // else
        } // fi
} catch (ParseException err) {
        System.out.println(err);
        System.exit(1);
        } //catch
        finally {
                new Hello().helloWorld(opt);
        } //finally
} //try

It's a robust system that attempts to avoid irrecoverable errors or, at least, to provide you with the option to give useful feedback to the user. Use it often, and your users will thank you!

Ref: https://red.ht/3EZc9OC