// Helene Martin, CSE 142
// Several methods that return booleans

import java.util.*;

public class BooleanDemo {
   public static void main(String[] args) {
      Scanner s = new Scanner(System.in);
      System.out.print("How old are you? ");
      int age = s.nextInt();
      
      boolean canVote = age >= 18;
      boolean isSunny = true;
      
      if (canVote && isSunny) {
         System.out.println("To the polls!");
      }
      
      if (!isPrime(age)) {
         System.out.println("Your age is NOT prime! =(");
      }
      
      System.out.println(bothOdd(5, 7)); // true
      System.out.println(bothOdd(6, 4)); // false
      System.out.println(bothOdd(5, 4)); // false
      System.out.println(bothOdd(0, 7)); // false
      System.out.println(bothOdd(1, 5)); // true
      System.out.println(bothOdd(-5, -7)); // true
      
      System.out.println(isVowel("i"));
      System.out.println(isVowel("q"));
      
   }
   
   // returns whether a value is a prime or not
   public static boolean isPrime(int value) {
      return factors(value) == 2;
      //       if (factors == 2) {
      //          return true;
      //       } else {
      //          return false;
      //       }
   }
   
   // counts and returns the factors of a given number
   public static int factors(int value) {
      int factors = 0;
      for (int i = 1; i <= value; i++) {
         if (value % i == 0) {
            factors++;
         }
      }
      return factors;
   }
   
   // bothOdd returns true if both parameters are odd, false otherwise
   public static boolean bothOdd(int num1, int num2) {
      boolean num1Odd = num1 % 2 != 0;
      boolean num2Odd = num2 % 2 != 0;
      
      return num1Odd && num2Odd;
   }
   
   // 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();
      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.equals("a") && !s.equals("e") ... use De Morgan's law
      return !isVowel(s);
   }
}