Finding frequency and probability of characters in a string

[Aberforth]

***Problem****In this program if the frequency is large (say, 9) the frequency shows it as 9.000000000006.

import java.io.*;
 
public class Freq {
 
    public static void main(String[] args) 
      {
        System.out.println("Type string : ");
        String str = "";
        InputStreamReader input = new InputStreamReader(System.in);
        BufferedReader reader = new BufferedReader(input);
 
 
        try 
        {
 
            str = reader.readLine();
 
        } 
        catch (Exception e) { }
        System.out.println("String is : " + str);//part 2 string input
 
        /*finding frequency of characters*/
        double len = str.length();
        double count = 0;
        double prob = 0;
        double ref = 1000;
        double freq = 0;
        double prqueue[] = new double[96];
        char charArr[] = new char[96];
        double temp = 0;
        char flag;
 
        for (int i = 0; i < 96; i++) 
           {
            char currChar = (char) (32 + i);
            for (int k = 0; k < len; k++)
            {
                char currStrChar = str.charAt(k);
                if (currChar == currStrChar) {
                    count = count + (1 / ref);//this is used if the file is too large
 
             }
 
            }
            freq = count * ref;
            prob = freq / len;
            if (freq != 0) 
           {
                System.out.println("occurence of " + currChar + ": " + freq + " and probability is : " + prob);
            }
            prqueue[i] = prob;
            charArr[i] = currChar;
            count = 0;
 
 
        }
 
 
        System.out.println();
        System.out.println();
        System.out.println("PRIORITY QUEUE :");
        /*priority queue*/
        for (int x = 0; x < 95; x++) {
            for (int y = 0; y < 95 - x - 1; y++) {
                if (prqueue[y] > prqueue[y + 1]) {
                    temp = prqueue[y];
                    flag = charArr[y];
                    prqueue[y] = prqueue[y + 1];
                    charArr[y] = charArr[y + 1];
                    prqueue[y + 1] = temp;
                    charArr[y + 1] = flag;
                }
            }
        }
 
        for (int x = 0; x < 95; x++) {
            if (prqueue[x] != 0) {
                System.out.println(charArr[x] + " has value in priority queue " + prqueue[x] + ", ");
            }
        }
    }
}

[copeg]

***Problem****In this program if the frequency is large (say, 9) the frequency shows it as 9.000000000006.

Why is that a problem? What do you expect/want to see?

[Aberforth]

actually the frequency should be an integer i.e,9.0000000000 and not 9.0000000006.

[Darryl.Burke]

actually the frequency should be an integer

Then why are you using a double?

db

[Aberforth]

i am using double because probability will have a decimal part.
but when i am going to find the frequency , the decimal part should be entirely zero.
for example, the string be: aaaabbbbbbbbbbbccc
the frequency of 'b' must be 11.
but when i run the program, the frequency is shown as 11.0000000000004.
i am confused about the .00000000004 part.