Answer:
// Scanner class is imported to allow program
// receive input
import java.util.Scanner;
// Solution class is defined
public class Solution {
// main method that signify beginning of program execution
public static void main(String args[]) {
// Scanner object scan is created
// it receive input via keyboard
Scanner scan = new Scanner(System.in);
// Prompt is display asking the user to enter number
System.out.println("Enter your three digit number: ");
// the user input is stored at userInput
int userInput = scan.nextInt();
// if-statement that check if user input is three digit
if(userInput < 100 || userInput > 999){
// if input is three digit; it display error
System.out.println("Error");
} else{
// the first digit is gotten as the quotient
// when the input is divided by 100
int firstDigit = userInput / 100;
// the second digit is gotten by dividing the
// result of the input modulus 100 by 10
int secondDigit = (userInput % 100) / 10;
// the third digit is gotten through
// userInput modulus 10
int thirdDigit = userInput % 10;
// the addition of the three digit is assigned to sum
int sum = firstDigit + secondDigit + thirdDigit;
// the sum is displayed to the user
System.out.println("The sum of the three digit is: " + sum);
}
}
}
Explanation:
The program is well commented and detailed. Images showing output of the program is attached.
//import the Scanner class to allow for user's inputs
import java.util.Scanner;
//Declare a class for the application
public class ThreeDigit {
//Declare a main method where execution begins
public static void main(String[] args) {
//Create an object of the Scanner class to allow user's inputs
Scanner input = new Scanner(System.in);
//Prompt the user to enter a 3-digit number
System.out.println("Enter a positive three-digit number");
//Receive the number with the scanner object created
//And store it in an int variable
int num = input.nextInt();
//Check if the number is within range.
//A 3-digit number is between 99 and 1000
//If it is within range
if(num > 99 && num < 1000){
//GET THE FIRST DIGIT
//The first digit is the result of
//the integer division of the 3-digit number with 100
int fdigit = num / 100;
//GET THE SECOND DIGIT
//The second digit is the result of the integer division of the
// remainder, when the 3-digit number is divided by 100,
// with 10 .
int sdigit = (num%100) / 10;
//GET THE THIRD DIGIT
//The third digit is the remainder when the 3-digit number is divided
// by 10 .
int tdigit = (num % 10);
//Sum the three digits
int sum = fdigit + sdigit + tdigit;
//print out the result
System.out.println("The sum of the three digits is : " + sum);
} //End of if statement
//If it is not within range
else {
//print out an error message
System.out.println("Error");
} // End of else statement
} //End of main method
} //End of class declaration
===========================================================
>> Enter a positive three-digit number
345
>> The sum of the three digits is : 12
============================================================
>> Enter a positive three-digit number
5678
>> Error
============================================================
The code has been written in Java. It contains comments explaining every segment of the code. Kindly go through the comments.
The actual lines of code are written in bold face to separate them from comments.
Sample outputs have also been provided to give a feel of what the program outputs.
