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package de.vogella.datastructures.list;

import java.util.Arrays;

public class MyList<E> {
    private int size = 0;
    private static final int DEFAULT_CAPACITY = 10;
    private Object elements[];

    public MyList() {
        elements = new Object[DEFAULT_CAPACITY];
    }

    public void add(E e) {
        if (size == elements.length) {
            ensureCapa();
        }
        elements[size++] = e;
    }


    private void ensureCapa() {
        int newSize = elements.length * 2;
        elements = Arrays.copyOf(elements, newSize);
    }

    @SuppressWarnings("unchecked")
    public E get(int i) {
        if (i>= size || i <0) {
            throw new IndexOutOfBoundsException("Index: " + i + ", Size " + i );
        }
        return (E) elements[i];
    }
}


package de.vogella.datastructures.list;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import static org.junit.Assert.assertTrue;

public class MyListTest {


    @Test(expected=IndexOutOfBoundsException.class)
    public void testMyList() {
        MyList<Integer> list = new MyList<Integer>();
        list.add(1);
        list.add(2);
        list.add(3);
        list.add(3);
        list.add(4);
        assertTrue(4 == list.get(4));
        assertTrue(2 == list.get(1));
        assertTrue(3 == list.get(2));

        list.get(6);
    }


    @Test(expected=IndexOutOfBoundsException.class)
    public void testNegative() {
        MyList<Integer> list = new MyList<Integer>();
        list.add(1);
        list.add(2);
        list.add(3);
        list.add(3);
        list.add(4);
        list.get(-1);
    }

    @Test(expected=IndexOutOfBoundsException.class)
    public void testList() {
        List<Integer> list = new ArrayList<Integer>();
        list.add(1);
        list.add(2);
        list.add(3);
        list.add(3);
        list.add(4);
        assertTrue(4 == list.get(4));
        assertTrue(2 == list.get(1));
        assertTrue(3 == list.get(2));

        list.get(6);
    }



}