printing unique char and their occurrence

Question

I am new to java and programming too. I have given an assignment to count the occurrence of unique character. I have to use only array. I have do the flowing code -

public class InsertChar{

    public static void main(String[] args){

        int[] charArray = new int[1000];
        char[] testCharArray = {'a', 'b', 'c', 'x', 'a', 'd', 'c', 'x', 'a', 'd', 'a'};

        for(int each : testCharArray){

            if(charArray[each]==0){
                charArray[each]=1;
            }else{
                ++charArray[each];
            }

        }

        for(int i=0; i<1000; i++){
            if(charArray[i]!=0){
                System.out.println( i +": "+ charArray[i]);
            }
        }
    }

}

For the testCharArray the output should be -

a: 4
b: 1
c: 2
d: 2
x: 2

But it gives me the following outpu -

How can I fix this?

score 3 · Answer 1 · answered May 30 '15 at 19:24

3

i is int, so you are printing the integer value of each char. You have to cast it to char in order to see the characters.

change

System.out.println( i +": "+ charArray[i]);

to

System.out.println( (char)i +": "+ charArray[i]);

answered May 30 '15 at 19:24

Eran

387,369
54
702
768

score 3 · Answer 2 · answered May 30 '15 at 19:24

3

You are printing the index as an int. Try casting it to a char before printing it:

for (int i=0; i<1000; i++){
    if (charArray[i]!=0){
        System.out.println( ((char) i) +": "+ charArray[i]);
    }
}

answered May 30 '15 at 19:24

Mureinik

297,002
52
306
350

score 2 · Answer 3 · edited May 23 '17 at 12:18

Your program is printing ascii representation of characters. You just need to convert the acsii numbers to chars.

public class InsertChar{

    public static void main(String[] args){

        int[] charArray = new int[1000];
        char[] testCharArray = {'a', 'b', 'c', 'x', 'a', 'd', 'c', 'x', 'a', 'd', 'a'};

        for(int each : testCharArray){

            if(charArray[each]==0){
                charArray[each]=1;
            }else{
                ++charArray[each];
            }

        }

        for(int i=0; i<1000; i++){
            if(charArray[i]!=0){
                System.out.println( **(char)**i +": "+ charArray[i]);
            }
        }
    }

}

This should work.

Further reading:

How to convert ASCII code (0-255) to a String of the associated character?

score 2 · Answer 4 · answered May 30 '15 at 19:30

2

You are printing the ASCII int representation of each char. You have to convert them to char by casting -

System.out.println( (char)i +": "+ charArray[i]);

answered May 30 '15 at 19:30

Mehmood Arbaz

285
1
3
11

score 1 · Accepted Answer · answered May 30 '15 at 19:24

Your testCharArray is an array of int. You have stored char in it. So you have to cast character to int. You have to make a change at your last for loop -

for(int i=0; i<1000; i++){
    if(charArray[i]!=0){
        System.out.println( (char)i +": "+ charArray[i]); //cast int to char.
    }
}

This casting make the int to char. Each character have an int value. For example -

'a' has 97 as it's int value
'b' has 98 as it's int value

printing unique char and their occurrence

5 Answers5