// Helene Martin, CSE 142
// Several methods that return booleans
// Note: great midterm practice...

import java.util.*;

public class MoreBoolean {
	public static void main(String[] args) {
		System.out.println(isAllVowels("aeiouAEIOU")); // true
		System.out.println(isAllVowels("aeiouAqEIOU")); // false
		
		
		System.out.println(hasNoVowels("tqqqaqr")); // false
		System.out.println(hasNoVowels("qwrrrtpppp")); // true
		
		System.out.println();
		System.out.println(digitSum(29107)); // 19
		System.out.println(digitSum(-23)); // 5
	}
	
	// isAllVowels
	public static boolean isAllVowels(String phrase) {
		// 0123
		// food
		for (int i = 0; i < phrase.length(); i++) {
			String s = phrase.substring(i, i + 1);
			// String s = phrase.charAt(i) + ""
			if (isNonVowel(s)) {
				return false;
			}
		}
		return true;
	}
	
	// hasNoVowels
	public static boolean hasNoVowels(String phrase) {
		for (int i = 0; i < phrase.length(); i++) {
			String s = phrase.substring(i, i + 1);
			// String s = phrase.charAt(i) + ""
			if (isVowel(s)) {
				return false;
			}
		}
		return true;
	}
		
	// isVowel returns whether a String is a vowel (a, e, i, o, or u), 
	// case-insensitively.
	public static boolean isVowel(String s) {
		s = s.toLowerCase(); // or use equalsIgnoreCase
		return s.equals("a") || s.equals("e") || s.equals("i") 
				|| s.equals("o") || s.equals("u");
	}
	
	// isNonVowel returns whether a String is any character except a vowel.
	public static boolean isNonVowel(String s) {
		//s = s.toLowerCase();
		//return !s.equals("a") && !s.equals("e" ... De Morgan's law
		return !isVowel(s);
	}
	
	// digitSum accepts an integer parameter and returns the sum of its digits
	//4934343 % 10 --> 3
	//4934343 / 10 --> 493434
	public static int digitSum(int value) {
		value = Math.abs(value);
		
		int sum = 0;
		while(value > 0) {
			int rightDigit = value % 10;
			sum = sum + rightDigit;
			
			value = value / 10;
		}
		return sum;
	}
}