ArrayList

public class ArrayList {
	Object[] objects = new Object[10];
	int index = 0;

	public void add(Object o) {
		if (index >= objects.length) {
			capacity();
		}
		objects[index++] = o;

	}
	
	
	public int size(){
		return index;
	}
	
	public Object get(int index){
		return objects[index];
	}


	private void capacity() {
		int len = objects.length * 2;
		Object[] temp = new Object[len];
		for (int i = 0; i < objects.length; i++) {
			temp[i] = objects[i];
		}
		objects = temp;

	}
	
	public String toString() {
		int len = objects.length;
		String s = "";
		for (int i = 0; i < len && objects[i] != null; i++) {
			s = s + objects[i] + " ";
		}
		
		return s;
	}

}

import static org.junit.Assert.*;

import mypack4.ArrayList;

import org.junit.Test;

public class ArrayListTest {

	@Test
	public void test() {
		ArrayList a = new ArrayList();
		for (int i = 0; i < 15; i++) {
			a.add(i);
		}

		for (int i = 0; i < 15; i++) {
			System.out.print(a.get(i));
			assertEquals(i, a.get(i));
		}
		System.out.println(a);
	}
	
	

}