Display the individual digits from the scanner input

Question

Varunkrishna 0 Junior Poster in Training

9 Years Ago

How do I display the individual integers from the scanner input stream for example if the user enters 500 I would like to display it as 5, 0, 0. Here is the code guys

import java.util.Scanner;
public class Digit {
    public static void main(String[] args) {
        int number, i = 0, num, digits;
        int[] digit;
        Scanner input = new Scanner(System.in);
        System.out.print("Please enter the digit: ");
        try{
            number = input.nextInt();
            num = number;
            digits = 0;
            while(num > 0){
                digits = num % 10;
                digit = new int[]{digits};          
                num = num / 10;             
                i++;                    
            }
            System.out.println("The length of the given: "+number+ " is: "+i);
            System.out.println("The Digits are: "+digit+" ,");

        }
        catch(Exception exception){
            exception.printStackTrace();

        }
        finally{
            input.close();
        }

    }
}

But when I execute this code I am getting an error

$ javac Digit.java
Digit.java:20: error: variable digit might not have been initialized
                        System.out.println("The Digits are: "+digit+" ,");
                                                              ^
1 error

How I fix this ?

display input java scanner stringbuilder

3 Contributors
16 Replies
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1 Week Discussion Span
Latest Post 9 Years Ago Latest Post by Varunkrishna

All 16 Replies

stultuske 1,116 Posting Maven

9 Years Ago

firstly, for digit, you don't need an array. and if you do use an array (or any other variable) don't initialize it within the while block. if it never runs, the variable won't be initialized, and thus not recognized.

anyway, your approach is a bit over the top. an easier approach would be to set the int into a String, then iterate over the chars, and add those all to a new String, separated by ','s.

stultuske 1,116 Posting Maven

9 Years Ago

you are using way too much variables.
drop the digit, digits, ... you don't need al that.

read input in int.
convert int to String.
instantiate a new StringBuilder "" (or String)
iterate over each char in the original String
  - if String(Builder) isEmpty
      -> append ", " to String(Builder)
  - append char to String
end-iteration

print int (originalNumber) and length of the original String
print the new String(Builder) 's value

stultuske 1,116 Posting Maven

9 Years Ago

it is not. if you look closely, you'll see that the second sequence is not the same as the first.
but, again, why are you making it so difficult? no division required. just transform it to a char array and print each element.

Slavi 94 Master Poster

9 Years Ago

Okay you've spent a week on this, now consider the following code .. as @stiltuske proposed use a char array and then print its elements

import java.util.Scanner;
public class Digit {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Please enter the digit: ");
        char[] numbers = ("" + input.nextInt()).toCharArray();
        for(int i = 0; i<numbers.length; i++){
            System.out.println(numbers[i]);
        }        
    }
}

Output:
Please enter the digit: 123

1
2
3

Edited 9 Years Ago by Slavi

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Varunkrishna 0 Junior Poster in Training · Answer 1 · 2015-03-02T00:08:41+00:00

Stultuske,
What do you mean by this:

an easier approach would be to set the int into a String, then iterate over the chars, and add those all to a new String, separated by ','s.

Did you mean that the variable in line number 5, int[] digit; should be changed to string array ?

Varunkrishna 0 Junior Poster in Training · Answer 2 · 2015-03-02T00:28:51+00:00

I have changed the above code to look like the following

...
while(num > 0){
    digits = num % 10;
    digit = new int[num];
    digit = new int[]{digits};          
    num = num / 10;             
    i++;
    System.out.print("The Digits are: "+digit+",");
}
...

This is the output I got in the console,

$ javac Digit.java
$ java Digit
Please enter the digit: 800
The Digits are: [I@55f96302 ,The Digits are: [I@3d4eac69 ,The Digits are:  [I@42a57993 ,The length of the given 800 is: 3

But I want it to be displayed as something like this
The Digits are: 8,0,0.

Varunkrishna 0 Junior Poster in Training · Answer 3 · 2015-03-05T02:05:26+00:00

Varunkrishna 0 Junior Poster in Training

9 Years Ago

stultuske

Thanks, I'll try it out and get back to you.

Varunkrishna 0 Junior Poster in Training · Answer 4 · 2015-03-08T03:23:20+00:00

stultuske
I could not get the line number 4

iterate over each char in the original String

import java.util.Scanner;
public class Digit {
    public static void main(String[] args) {
        int number, i = 0, num, digits;
        String digit;
        Scanner input = new Scanner(System.in);
        System.out.print("Please enter the digit: ");
        try{
            number = input.nextInt();
            num = number;
            digits = 0;
            while(num > 0){
                digits = num % 10;
                digit = Integer.toString(num);
                StringBuilder digitString = new StringBuilder();
                num = num / 10;             
                i++;
                if(digitString.toString().isEmpty()){
                    digitString.append(digit);
                    System.out.println("Digits are: "+digitString);

                }
            }
            System.out.println("The length of the given "+number+ " is: "+i);
            //System.out.println("The Digits are: "+digit+" ,");

        }
        catch(Exception exception){
            exception.printStackTrace();

        }
        finally{
            input.close();
        }

    }
}

And this is the output I am getting

$ java Digit
Please enter the digit: 654
Digits are: 654
Digits are: 65
Digits are: 6
The length of the given 654 is: 3

Varunkrishna 0 Junior Poster in Training · Answer 5 · 2015-03-08T03:37:51+00:00

Why is it printing the digits two times ?

...
while(num > 0){
                digits = num % 10;
                digit = Integer.toString(num);
                StringBuilder digitString = new StringBuilder();
                num = num / 10;             
                i++;
                for(int j = 0; j < digit.toString().length(); j++)
                {
                    if(digitString.toString().isEmpty()){
                        digitString.append(digit);
                        //System.out.println("Digits are: "+digitString);

                    }
                    //digitString.append(digit);            
                    System.out.println("The digits are: "+digitString.charAt(j));

                }
            }



$ java Digit
Please enter the digit: 654
The digits are: 6
The digits are: 5
The digits are: 4
The digits are: 6
The digits are: 5
The digits are: 6
The length of the given 654 is: 3

Varunkrishna 0 Junior Poster in Training · Answer 6 · 2015-03-08T12:02:04+00:00

Slavi,
Thank you so much for taking time to reply back to this thread, but I want something like this, If the user enters 12345 as the digit. The digits are 1,2,3,4,5 in the output.

Varunkrishna 0 Junior Poster in Training · Answer 7 · 2015-03-08T12:03:55+00:00

stultuske

import java.util.Scanner;
public class Digit2 {
    public static void main(String[] args) {
        int number, i = 0, num, digits;
        String digit;
        Scanner input = new Scanner(System.in);
        System.out.print("Please enter the digit: ");
        try{
            number = input.nextInt();
            num = number;
            digits = 0;
            digits = num % 10;
            digit = Integer.toString(num);
            StringBuilder digitString = new StringBuilder();
            for (int j = 0; j< digit.length(); j++){
                char numChar = digit.charAt(j);
                if(digitString.toString().isEmpty()){
                    digitString.append(", ");
                }
                System.out.println("The digits are: "+numChar); 
                digitString.append(numChar);                
            }               
            System.out.println("The length of the given "+number+ " is: "+digit.length());
            System.out.println("The string Builder value is: "+digitString);

        }
        catch(Exception exception){
            exception.printStackTrace();

        }
        finally{
            input.close();
        }

    }
}

I am somewhat close. Here is the output that I had got in the console.

$ java Digit2
Please enter the digit: 12345
The digits are: 1
The digits are: 2
The digits are: 3
The digits are: 4
The digits are: 5
The length of the given 12345 is: 5
The string Builder value is: , 12345

But why is it printing something like this The string Builder value is: , 12345 as the output ? What is wrong ?

Slavi 94 Master Poster Featured Poster · Answer 8 · 2015-03-08T12:06:14+00:00

Sorry I am not sure what do you mean, as it is now it will output each of those values, here's example of my terminal

Varunkrishna 0 Junior Poster in Training · Answer 9 · 2015-03-08T12:08:24+00:00

stultuske
Alas Finally I got what I needed thank you so much.

import java.util.Scanner;
public class Digit2 {
    public static void main(String[] args) {
        int number, i = 0, num, digits;
        String digit;
        Scanner input = new Scanner(System.in);
        System.out.print("Please enter the digit: ");
        try{
            number = input.nextInt();
            num = number;
            digits = 0;
            digits = num % 10;
            digit = Integer.toString(num);
            StringBuilder digitString = new StringBuilder();
            for (int j = 0; j< digit.length(); j++){
                char numChar = digit.charAt(j);
                if(!digitString.toString().isEmpty()){
                    digitString.append(", ");
                }
                System.out.println("The digits are: "+numChar); 
                digitString.append(numChar);                
            }               
            System.out.println("The length of the given "+number+ " is: "+digit.length());
            System.out.println("The string Builder value is: "+digitString);

        }
        catch(Exception exception){
            exception.printStackTrace();

        }
        finally{
            input.close();
        }

    }
}

Output:

$ java Digit2
Please enter the digit: 12345
The digits are: 1
The digits are: 2
The digits are: 3
The digits are: 4
The digits are: 5
The length of the given 12345 is: 5
The string Builder value is: 1, 2, 3, 4, 5

Varunkrishna 0 Junior Poster in Training · Answer 10 · 2015-03-08T12:09:46+00:00

Varunkrishna 0 Junior Poster in Training

9 Years Ago

Slavi
Check the above output. Thanks so much.

Slavi 94 Master Poster Featured Poster · Answer 11 · 2015-03-08T12:14:41+00:00

But it is the same thing :D except that I was printing just the numbers without the string "The digits are: " and the length. If I add the string in the print and another line it becomes this and prints the same thing

import java.util.Scanner;
public class Digit {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Please enter the digit: ");
        char[] numbers = ("" + input.nextInt()).toCharArray();
        for(int i = 0; i<numbers.length; i++){
            System.out.println("The digits are " + numbers[i]);
        }
        System.out.println("The length of the numbers entered by the user is: " + numbers.length);        
    }
}

when you run the program then ..

Please enter the digit: 12345
The digits are 1
The digits are 2
The digits are 3
The digits are 4
The digits are 5
The length of the numbers entered by the user is: 5

Varunkrishna 0 Junior Poster in Training · Answer 12 · 2015-03-08T12:19:07+00:00

Salvi
Thanks man. I have been trying to achive the line number 9(The string Builder value is: 1, 2, 3, 4, 5) of my output. :)

Display the individual digits from the scanner input

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