Can somebody check my codes?(Counting numbers)

This program is about counting the number of digits that exist in a string
there is no compile error on it but there is an error in the logics that i cant find it. So can somebody have a look at it, if you cant tell me the direct answer then please give me some hints. Thanks

Here is my codes

Code:

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public class OccurrenceString
      {
            public static void main (String[] args)
            {
                                    System.out.println("SSN is 343 32 4545 and ID is 434 34 4323");

                                String SSNandID = "SSN is 343 32 4545 and ID is 434 34 4323";

                                int[] countNum = count(SSNandID);

                       

                                //display count array
                                for(int i=0; i < countNum.length; i++)
                                {
                                        if(countNum[i] != 0)
                    System.out.println(i +" appears "+ countNum[i] + ((countNum[i]==1)?" times.":" times."));
                                }
                        }//end of main

        public static int[] count(String SSNandID)
        {
                int counts[] = new int[10];

                for(int i = 0; i< SSNandID.length(); i++)
                {
                        if(Character.isDigit(SSNandID.charAt(i)))
                        {

                        counts[SSNandID.charAt(i)]++;
                    }
                }//end of for
                return counts;

        }//end of count method

        }//end of OccurrenceString

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This line might cause arrayIndexOutofBoundsExeption

Code:

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public static int[] count(String SSNandID)
        {
                [COLOR="Red"]int counts[] = new int[10];[/COLOR]

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try this:

Code:

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public static int[] count(String SSNandID)
        {
                [COLOR="Red"]int counts[] = new int[SSNandID.length()];[/COLOR]

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Quote:

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Originally Posted by azzaiel

This line might cause arrayIndexOutofBoundsExeption

Code:

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public static int[] count(String SSNandID)
        {
                [COLOR="Red"]int counts[] = new int[10];[/COLOR]

---

try this:

Code:

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public static int[] count(String SSNandID)
        {
                [COLOR="Red"]int counts[] = new int[SSNandID.length()];[/COLOR]

---

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i cant use that because that is the length of the string. i used 10 in that array becuase there i wanted the array starts from 0-9 and increment a number whenever a number exists in the SSNandID string. its like counting how many 1s,2s,3s...9s in that string.
Thank you for your respond

ok sorry

Code:

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public static int[] count(String SSNandID)
        {
                int counts[] = new int[10];

                for(int i = 0; i< SSNandID.length(); i++)
                {
                        if(Character.isDigit(SSNandID.charAt(i)))
                        {

                        counts[i]++;
                    }
                }//end of for
                return counts;

        }//end of count method

---

change that to this:

Code:

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public static int[] count(String SSNandID) {
                int counts[] = new int[11];
               
                for (int i = 0; i < SSNandID.length(); i++) {
                       
                        if (Character.isDigit(SSNandID.charAt(i))) {
                                final Character cNum = SSNandID.charAt(i);
                                final String sNum = cNum.toString();
                            int num = Integer.parseInt(sNum);
                            counts[num] += 1;
                        }
                }// end of for
                return counts;

        }

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tell me if you have questions

@OP: Much similar to the switch-case logic. If you can start from the basis logic, easy to find the solution. ;)

Just adding more..

Following is the switch-case logic

Code:

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                switch(SSNandID.charAt(i)) {
                    case '0':
                        counts[0]++;
                        break;
                    case '1':
                        counts[1]++;
                        break;

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No compare it with azzaiels' code. Doing the same thing in much much better way. :)

Thanks guys i got it!!!

@Eranga

so your gona make a case from case'0' to case'10' and hard code the value of the index of the array hmmm hows that better?

Quote:

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Originally Posted by azzaiel

@Eranga

so your gona make a case from case'0' to case'10' and hard code the value of the index of the array hmmm hows that better?

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No way, that's the bad way I can program the logic. What I'm trying to point there is, that's the basic logic and implementation we can follow. Very basis about the deal with multiple options.

I never advice to follow that way in any case.

My humble 2c's worth...

Code:

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package forums;

class FrequencyOfDigitsTest
{
  public static void main(String[] args) {
    try {
      System.out.println(java.util.Arrays.toString(frequencyOfDigits("0123456789012345")));
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  public static int[] frequencyOfDigits(String text) {
    int counts[] = new int[10];
    for ( char c : text.toCharArray() ) {
      if ( Character.isDigit(c) ) {
        counts[Integer.parseInt(String.valueOf(c))]++;
      }
    }
    return counts;
  }
}

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