MergeStrings java

MergeStrings.java

static String MergeStrings(String[] strings) {
    Map<Character, Integer> charCount = new HashMap<>();

    for (String str : strings) {
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);

            if (Character.isAlphabetic(c)) {
                charCount.merge(c, 1, (a, b) -> a + b);
            }
        }
    }

    StringBuilder stringBuilder = new StringBuilder();
    for (Map.Entry<Character, Integer> entry : charCount.entrySet()) {
        stringBuilder.append(new String(new char[entry.getValue()]).replace("\0", entry.getKey().toString()));
    }


    return stringBuilder.toString();
}