Question

write a recursive method to determine if the entire string is uppercase character

Answer 1

import java.util.Scanner;

public class IsStringUppercase {

    public static boolean isUppercase(String s) {
        if (s.isEmpty())    // base case
            return true;
        return !(s.charAt(0) >= 'a' && s.charAt(0) <= 'z') && isUppercase(s.substring(1));   // recursive case
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter a string: ");
        String str = in.nextLine();
        if (isUppercase(str)) {
            System.out.println(str + " is in uppercase");
        } else {
            System.out.println(str + " is not in uppercase");
        }
    }
}