Exception in thread "main" java.lang.Error: Unresolved compilation problems:
    The local variable characterArray may not have been initialized
    The local variable characterArray may not have been initialized
    The local variable characterArray may not have been initialized
 
    at BubbleSort.main(BubbleSort.java:15)

import java.util.Arrays;
import java.io.*;
 
public class BubbleSort {
 
	/**
	 * @param args
	 */
	public static void main(String[] args) throws IOException{
		BufferedReader in = new BufferedReader (new InputStreamReader(System.in));
		char characterArray[];
 
		System.out.print("Enter Name:\t");
 
		Arrays.sort(characterArray);
 
        for (int i = 0; i < characterArray.length; i++)
        {
             System.out.print(characterArray[i]);
             System.out.print(", ");
        }
 
 
	}
 
}

char characterArray[] = new char[charArraySize];

String = input;
int num;
 
System.out.print("******");
num = Integer.parseInt (input = in.readLine());

char characterArray[20] = new char[charArraySize];

char characterArray[] = new char[charArraySize];

char characterArray[] = new char[20];