/**
 * Author: Josiah Yoder
 * Class: SE1011-011
 * Lesson: Week 5, Day 1
 */

import java.text.ParseException;
import java.util.Scanner;
import javax.swing.JOptionPane;
import java.util.Random;

public class Example011_5_1 {
    public static void main(String[] ignored) {
        Scanner in = new Scanner(System.in);

        // Parse the first digit with Integer.parseInt()
        System.out.println("Enter a number:");
        String str = in.next();
        int number = 0;
        if(str.length() > 0) {
            char c = str.charAt(0);
            String str2 = str.substring(0, 1);
            // alternative: String str2 = Character.toString(str.charAt(0));
            boolean isDigit = Character.isDigit(c); //not char here.
            if(isDigit) {
                number = Integer.parseInt(str2);
            }
        }


        // Parse the first digit with Character.digit(c,10);
        System.out.println("Enter a number:");
        str = in.next();
        number = 0;
        if(str.length() > 0) {
            char c = str.charAt(0);
            boolean isDigit = Character.isDigit(c); //not char here.
            if(isDigit) {
                int digit = Character.digit(c,10);
            }
        }

        System.out.println("The first digit is "+number);

        // Use Math.pow to raise 5 to the power of 4
//        double a = 5;
//        double b = 4;
//        Math.pow(5,4);


        // Very simple pseudo-random number generator
//        int limit = 7;
//        int increment = 4;
//        int currentValue = 0;
//        for(int i = 0; i < 10; i++) {
//            currentValue+=increment;
//            currentValue =  currentValue % limit;
//            System.out.println("The "+i+"th random number is "+currentValue);
//        }

        // Using Java's random number generator
//        Random generator = new Random();
//        generator.setSeed(System.currentTimeMillis()); // Poor practice in Java, good practice in other languages.
//        int randomNumber;
//        for(int i = 0; i < 10; i++) {
//            randomNumber = generator.nextInt(5);
//            System.out.println("The "+i+"th random number is "+randomNumber);
//        }
    }
}