array of char

Hi,
I have a problem with array. Inputs are size of binary number and integer. I need to create char array from that integer with leading zeroes (I need those 0`s later for a logical operations). Problem is that I can not get those 0`s as a result. Can anyone help me, please?

Code:

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public class adder {
       
        static int size;
       
        public static void main (String[]args){
       
        Scanner input = new Scanner (System.in);
        System.out.println("size of binary number");
        size = input.nextInt();
        System.out.println("enter number?");
        int firstNumber = input.nextInt();
        String binaryNumber = Integer.toBinaryString(firstNumer);
        addZeroes (binaryNumber);
        char[] firstList = new char [size];
        firstList = binaryNumber.toCharArray();
        System.out.println(firstList);
        }
       
        public static String addZeroes(String a) {
                int i;
                i = a.length();
                if (i == size)
                        return a;
                else
                {
                        int j = size - i;
                        for (int k=0; k<j; k++)
                        {
                                a = "0" + a;                               
                        }
                        return a;               
                }
        }

}

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Code:

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main {
binaryNumber = addZeroes(binaryNumber);
}


public static String addZeroes(String a) {
                while (a.length() != size)
                    a = "0"+a;
                return a;               
        }

---

should work.

EDIT: Btw, printing an array will just show you the name of the object. You should loop through the array and print each element to print the contents.

Remember that Strings are immutable. So this

Code:

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addZeroes(binaryNumber);

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creates a String with leading zeros but then discards the String.

You want to get that String returned and use it. i.e.,

Code:

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      //!! addZeroes(binaryNumber);
      //!! char[] firstList = new char[size];
      //!! firstList = binaryNumber.toCharArray();
      String addedZeros = addZeroes(binaryNumber);  // get the result of the method
      char[] firstList = addedZeros.toCharArray();  // and use it here

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Also, note that I added code tags to your original post to help make it readable. Please see my signature to learn how to do this yourself.

Oh, and welcome to the forum!

Fubarable,
thank you!
Just, in last line char[] is not needed (duplicate local variable).
Thank you again!

Quote:

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Originally Posted by sinisab

Fubarable,
thank you!

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You're quite welcome.

Quote:

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Just, in last line char[] is not needed (duplicate local variable).

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That's because in my code I declared the char array variable on the same line that I created it (via String#toCharArray() method).

I feel ignored xD

Please mark the thread as SOLVED. :)

Supamagier,
Sorry! Thank you, also. Your method AddZeros is efficient than mine, so I will use that.
I will mark this as solved, just to see how to do that. I`m new in forum and Java also. Forgive me.

Yep, super was first with the good idea and should get credit. Thank you, sinisab for correcting this.

lol supa...I too feel ignored .:( ...I want a bear hug Fuda.;)

if you only need a string representation then this is your friend

Code:

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                NumberFormat nf = NumberFormat.getInstance();
                nf.setMinimumIntegerDigits(11);
                nf.setGroupingUsed(false);
                System.out.println(nf.format(1234));

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