/**
 * Asks user to input their family's age and displays the average of the ages.
 *
 * @Laura
 * @1.0
 */

import java.util.*;

public class Age {
    public static void main (String[] args) {
        Scanner s = new Scanner(System.in); //initializing variables and ArrayList
        ArrayList<Integer> ages = new ArrayList<Integer>();
        String age = "";
        double average = 0.0;
        double sum = 0.0;

        System.out.print("Enter your age: "); //prompts for age
        age = s.nextLine();

        while (!checkIfStringIsNumber(age) || Integer.parseInt(age) < 0) { //catches if the age entered isn't a number or if the age entered is negative
            System.out.print("That is not a valid answer. Enter your age: "); //re-prompts
            age = s.nextLine();
        }
        ages.add(Integer.parseInt(age)); //converts age into an int and stores in the ArrayList

        while (Integer.parseInt(age) > 0) { //exits loop if the age entered is negative
            System.out.print("Enter you family member's age. If you have no more family members, enter a negative number: "); //prompts for family member age
            age = s.nextLine();
            while (!checkIfStringIsNumber(age)) {
                System.out.print("That is not a valid answer. Enter your family member's age: ");
                age = s.nextLine();
            }
            if (Integer.parseInt(age) >= 0) { //if the age is positive, add it to the array
                ages.add(Integer.parseInt(age));
            }
        }

        for (int i = 0; i < ages.size(); i++) {
            int temp = ages.get(i);
            sum += temp; //iterates through ages ArrayList and adds each item in ArrayList to the sum
        }
        average = sum/ages.size(); //divides the sum by the number of ages
        System.out.println("The average age of your family is " + average + "."); //outputs average age
        System.out.println("Program terminated.");
    }
    public static boolean checkIfStringIsNumber(String s) { //method to check if a string is a number
        try {
            Integer.parseInt(s);
        } catch (NumberFormatException e) { //if string isn't a number, return false
            return false;
        }
        return true;
    }
}