Separating the Digits in an Integer - exercise from Deitel's Java book

Question

Exercise from Deitel\'s \"Java How To Program\" 10th edition:

2.30 (Separating the Digits in an Integer) Write an application that inputs one number c

Answer 1

I also just started with java and with this book, and this is the code that did the tric for me. Forgive me if i did something strange... :)

import java.util.Scanner;

public class SeparateNumber
{
    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);
        int nr, nr1, nr2, nr3, nr4, nr5;

        System.out.print("Enter a number with 5 digits: ");
        nr = in.nextInt();

        nr1 = nr / 10000;
        nr2 = (nr % 10000) / 1000;
        nr3 = ((nr % 10000) % 1000) / 100;
        nr4 = (((nr % 10000) % 1000) % 100) / 10;
        nr5 = (((nr % 10000) % 1000) % 100) % 10;

        System.out.printf("%d%s%d%s%d%s%d%s%d%n", nr1, " ", nr2, " ", nr3, " ", nr4, " ", nr5);
    }
}

Answer 2

Below code handles splitting on any int in integer range.

Steps:

1. Convert int to String
2. Convert each character of String to int by using Integer.parseInt
3. Store int digits in int[]
4. Print int[]

Sample code:

import java.util.*;

public class SplitDigits{
    public static void main(String args[]) throws Exception {
        System.out.println("Enter number:");
        Scanner sc = new Scanner(System.in);
        int number = sc.nextInt();
        System.out.println("You have entered:"+number);
        String str = String.valueOf(number);
        int length = str.length();
        if ( length > 0){
            int[] digits = new int[length];
            for ( int i=0; i < length; i++){
                digits[i] = Integer.parseInt(String.valueOf(str.charAt(i)));
            }
            for ( int i=0; i < digits.length; i++){
                System.out.println("Digits:"+digits[i]);
            }
        }

    }
}

output:

java SplitDigits
Enter number:
123456789
You have entered:123456789
Digits:1
Digits:2
Digits:3
Digits:4
Digits:5
Digits:6
Digits:7
Digits:8
Digits:9

Answer 3

You know that the number is 5 digit long.

What about

number / 10 000 to retrieve the first digit.
number = reminder
number / 1000 to retrieve the second digit.
number = reminder
number / 100 to retrieve the third digit.
number = reminder
number / 10 to retrieve the fourth digit.
and reminder is the 5th one.

Answer 4

Try something like this

String str1 = "";
int a = 12345;
while(a>0)
{
  int b = a%10;
  str1 = str1 + String.valueOf(b+" ");
  a = a/10;
}
StringBuilder str = new StringBuilder(str1);
System.out.println(str.reverse());

Answer 5

Answer is:

//your package name

import java.util.Scanner; //for input the userin
public class SeperateDigit {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        System.out.printf("Enter a 5 digit number: ");
        int number = input.nextInt();

        int number1 = number/100000;
        int arrange = number%10000;
        int number2 = arrange/1000;
        int number3 = (arrange % 1000) /100;
        int number4 =(( arrange % 1000) % 100) / 10;
        int number5 = ((arrange % 1000) % 100) % 10;

        System.out.printf("%d %d %d %d %d", number1,number2,number3,number4, number5);
    }
}

and Result is

Enter a 5 digit number: 422339
4 2 3 3 9

Answer 6

Try this:

import java.util.*;
public class DigitsDisplay
{
    public static void main (String[] args)
    {
        Scanner input = new Scanner (System.in);
        int digit;
        System.out.print("Enter a positive number: ");
        digit = input.nextInt();
        int power = 1;
        while (power <= digit) {
            power *= 10;
        }
        power /= 10;
        while (power > 0) {
            System.out.println(digit/power);
            digit %= power;
            power /= 10;
        }
    }
}