Coding Interview - Check for Pangram

publicstaticvoid main(String[] args){Scanner scanner =newScanner(System.in);String input = scanner.nextLine();System.out.println(isPangram(input)?"pangram":"not pangram");}staticboolean isPangram(String input){boolean isPangram =false;if(input ==null|| input.length()<26){return isPangram;}

    input = input.toLowerCase();char[] charArray = input.toCharArray();Set<Character> charSet =newHashSet<>();for(char c : charArray){if(Character.isLetter(c)&&(!Character.isWhitespace(c))){
            charSet.add(c);}}if(charSet.size()==26){
        isPangram =true;}return isPangram;}