import java.util.*;
import java.io.*;

// Notes:
// translation from array to ArrayList:
//     String[]          => ArrayList<String>
//     new String[10]    => new ArrayList<String>()
//     a.length          => list.size()
//     a[i]              => list.get(i)
//     a[i] = value;     => list.set(i, value);
// new operations:
//     list.remove(i);     --remove the ith value
//     list.add(value);    --appends a value
//     list.add(i, value); --adds at an index
//     list.clear()        --remove all value
//     list.toString();    --nice String of the list
//
// Wrapper classes (for primitives):
//     int     => Integer
//     double  => Double
//     char    => Character
//     boolean => Boolean
public class Monday {
    public static void main(String[] args) throws FileNotFoundException {
        // Array version of reading a file into an array.
        String[] lines = new String[1000];
        Scanner input = new Scanner(new File("data.txt"));
        int lineCount = 0;
        while (input.hasNextLine()) {
            String line = input.nextLine();
            lines[lineCount] = line;
            lineCount++;
        }
        
        System.out.println(lines[0]);
        System.out.println(lines[lineCount - 1]);


        // ArrayList version of reading a file.
        ArrayList<String> lines2 = new ArrayList<String>();
        Scanner input2 = new Scanner(new File("data.txt"));
        while (input2.hasNextLine()) {
            String line = input2.nextLine();
            lines2.add(line);
        }
        
        System.out.println(lines2.get(0));
        System.out.println(lines2.get(lines2.size() - 1));

        // Manipulating ArrayLists for integer values
        ArrayList<Integer> list2 = new ArrayList<Integer>();
        list2.add(1);
        list2.add(-1);
        list2.add(42);
        int numElements = list2.size();
        int first = list2.get(0);
        System.out.println(list2);
    }
}