Example: Filter String Characters in Java

// Filter String Characters
public class Main {
    public static void main(String[] args) {
        String input = "P@sswOrd123!";
        int uppercaseCount = 0;
        int lowercaseCount = 0;
        int digitCount = 0;
        int specialCharCount = 0;
        StringBuilder filteredString = new StringBuilder();

        // Step 1: Iterate through each character in the string
        for (char ch : input.toCharArray()) {
            if (Character.isUpperCase(ch)) {
                uppercaseCount++;
                filteredString.append(ch); // Add to filtered string
            } else if (Character.isLowerCase(ch)) {
                lowercaseCount++;
                filteredString.append(ch);
            } else if (Character.isDigit(ch)) {
                digitCount++;
                filteredString.append(ch);
            } else {
                specialCharCount++;
                // Do not append special characters to filteredString
            }
        }

        // Step 2: Print the counts and the filtered string
        System.out.println("Original String: " + input);
        System.out.println("Uppercase letters: " + uppercaseCount);
        System.out.println("Lowercase letters: " + lowercaseCount);
        System.out.println("Digits: " + digitCount);
        System.out.println("Special characters: " + specialCharCount);
        System.out.println("Filtered (Letters & Digits Only): " + filteredString.toString());
    }
}