Thread: Help with String based program!!!

The Question is:
Write a program to input a string and print the frequency of each character.
Example:
INPUT: COMPUTER HARDWARE
OUTPUT: CHARACTERS FREQUENCY
A 2
C 1
AND SO ON...
The source code i wrote was:

import java.io.*;
class CharCount
{
public static void main(String args[])throws IOException
{
int i,h,k;
String a="AZazAz^_^";
int v=a.length();
System.out.println("Character"+"\t"+"FREQUENCY");
System.out.println(v);//here*
for(i=65;i<123;i++)
{h=0;
for(k=0;k<v;k++)
{
if (a.charAt(k)==i)
h++;
}
System.out.println(a.charAt(k) + "\t" + h);}}//#

}

There were no compilation errors.
But when i ran it, the program executed till *.

And the following errors came up:
java.lang.StringIndexOutOfBoundsException: String index out of range:9
at java.lang.String.charAt(String.java:686)
at CharCount.main(CharCount.java.18)

and the source code opened up with error in line #.

Can some please help me with this. I m really stuck up. Urgent help neccesary. Thanks in advance.

here's my implementation.

import java.io.*;
class CharCount
{
    public static void main(String args[]) throws IOException
    {
        int i,h,k;
        String a="bcDedAZazAz^_^";
        int v=a.length();
        char[] toChar = a.toLowerCase().toCharArray(); //get string to char array
        char[] charStore = new char[ v ]; // store characters found
        int [] charCountStore = new int[ v ]; //store count of characters found
        for(i=0;i<v;i++) { charCountStore[i]=0;} //initialize count to 0
        System.out.println("Character"+"\t"+"FREQUENCY");
        for(i=0;i< v; i++){
            if ( isInArray( charStore ,toChar[i] ) ){
                for(h=0;h<v;h++){
                    if ( Character.valueOf( charStore[h]).equals(toChar[i]) ){
                        // increase count if found in the charStore array
                        charCountStore[h]++;
                    }
                }
            }else{
                charStore[i] = toChar[i];
                charCountStore[i]++;
            }
        }
        for(i=0;i<v;i++){
            System.out.printf("%c\t\t%d\n", charStore[i],charCountStore[i] );
        }
    }
 
    public static boolean isInArray ( char[] a , char c){
        // check if character is in array, if yes, return true
        boolean found=false;
        for(int i=0;i< a.length; i++){
            if ( Character.valueOf(a[i]).equals(c) ){
                found=true;
                break;
            }
        }
        return found;
    }
 
}

import java.io.*;
class CharCount
{
public static void main(String args[])throws IOException
{
int i,h,k;
String a="AZazAz^_^";
int v=a.length();
System.out.println("Character"+"\t"+"FREQUENCY");
System.out.println(v);//*
for(i=65;i<123;i++)
{h=0;
for(k=0;k<v;k++)
{
if (a.charAt(k)==i)
h++;
}
System.out.println(a.charAt(k-1) + "\t" + h);}}//#

}

The correction was at line # itself.
I neede to write a.chatAt(k-1).
It was because when a loop executes, then the iteration is executed, so at that time 'k' was 9, which did not exist.
Thats all folks!!!

Thanks @JavaHater.