Why not this simple way? - java help on CodeGym

The validator says I'm not counting lowercase letters while I think I am. Or am using the regex the wrong way in line 23? I tried eualsIgnoreCase(), it didn't work either. I've also tried some more complicated code, in which I used StringBuilder and Treeset, see below). In this variant the validator admitted I was counting upperCase letters, too, but my code still didn't pass the third requirement (though I thought I counted and displayed the number of alphabetic characters). Is the problem with the way my while-loop reads data from the file?..

public class Solution {
    public static void main(String[] args) throws FileNotFoundException, IOException, IndexOutOfBoundsException {
        String fileName = args[0];
        //String fileName = "C:\\Users\\passe\\Documents\\Input.txt";
        FileInputStream fis = new FileInputStream(fileName);

        int x;
        StringBuilder data = new StringBuilder();

        while (fis.available() > 0) {
            x = fis.read();
            char letter = (char) x;
            data.append(String.valueOf(letter));
        }

        String ABS = data.toString().replaceAll("[^a-zA-Z]", "");
        TreeSet<Character> mySet = new TreeSet<>();
        for (int i = 0; i < ABS.length(); i++) {
            mySet.add(ABS.charAt(i));
        }
        System.out.println(mySet.size());
        fis.close();
    }

String fileName = "C:/temp/result.txt"; int numberOfLetters = 0; try (BufferedReader bufferedReader = new BufferedReader(new FileReader(fileName))) { while (bufferedReader.ready()) { if(Character.isLetter(bufferedReader.read())){ numberOfLetters++; } } System.out.println(numberOfLetters); }

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Pavel281185 Backend Developer

16 August, 17:01

I think that equals nad regex are not good friends 😁, try this.

if (String.valueOf(letter).matches("[a-zA-Z]"))

Check Java doc. There is always more than one solution:

Evgeniia Shabaeva

Level 32 , Budapest, Hungary

28 August, 08:17

Thank you so much for pointing at the problem) It really helped!

Guadalupe Gagnon

Level 37 , Tampa, United States

16 August, 16:12

The problem with this is the line:

if (String.valueOf(letter).equals("[a-zA-Z]")) abcCounter++;

The .equals() method does not accept a regex, so it is testing if the string is the same as the literal that you passed in. See example:

// this is true
System.out.println("[a-zA-Z]".equals("[a-zA-Z]"));

// this is false
System.out.println("a".equals("[a-zA-Z]"));

The problem with your code using a TreeSet is that it should count all the letters and not just the unique letters. For example the word "subscriptions" has 13 letters in it but your code will output 10 because it only has 10 unique letters.

28 August, 08:24

Thank you so much! I see now I didn't need this TreeSet at all. So, I filtered the symbols read from the stream to see which of them were letters, appended them to my StringBuilder and counted its length.