CharCheck.java

import java.util.Scanner;
public class CharCheck {
  public static void main(String[] args) 
  {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter a character : ");
        String input = scanner.next();  //String is not primitive data type 

        char ch = input.charAt(0);
        if(Character.isLowerCase(ch))
        {
                System.out.println(ch + " is lowercase letter.");
                System.out.println(" => to uppercase letter :"+ Character.toUpperCase(ch));
        }
        else if (Character.isUpperCase(ch))
        {
                System.out.println(ch + " is a upperchase letter");
                System.out.println(" => to lowercase letter : "+ Character.toLowerCase(ch));
        }else if(Character.isDigit(ch))
        {
                System.out.println(ch + " is a digit number ");  
        }
  }
}