Exercise18_14.java

package ch_18;

import java.util.Scanner;

/**
 * *18.14 (Find the number of uppercase letters in a string)
 * Write a recursive method to return the number of uppercase letters in a string.
 * <p>
 * Write a test program that prompts the user to enter a string and displays the number of uppercase letters in
 * the string.
 */
public class Exercise18_14 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter a String: ");
        String s = in.nextLine().trim();
        System.out.println("The number of uppercase letters in " + s + " is: " + numUpperCase(s, 0, 0));

    }

    static int numUpperCase(String str, int idx, int count) {
        if (idx == str.length()) {
            return count;
        }
        if (Character.isUpperCase(str.charAt(idx))) {
            count++;
        }
        return numUpperCase(str, ++idx, count);
    }
}