MyArray.java

package rc2;

/**
 *
 * @author khayyamsaleem A class that creates an interface for an array
 * @param <E>
 *            generic parameter
 */
public class MyArray<E> {
	private E[] data;
	private int length;
	private int cur = 0;

	private static class Node<E> {
		E data;
		int num;

		public Node(E data, int num) {
			this.data = data;
			this.num = num;
		}

		public String toString() {
			return "(" + data.toString() + ", " + num + ")";
		}
	}

	/**
	 * sets cur to first null spot in array
	 */
	private void setCur() {
		for (int i = 0; i < this.length; i++) {
			if (this.data[i] == null) {
				this.cur = i;
				break;
			}
		}
	}

	/**
	 * Constructor for the MyArray class
	 *
	 * @param length
	 *            the fixed size of the array
	 */
	@SuppressWarnings("unchecked")
	public MyArray(int length) {
		this.length = length;
		this.data = (E[]) new Object[length];
	}

	/**
	 * a get method for our array
	 *
	 * @param index
	 *            index of item to retrieve
	 * @return item at given index
	 */
	public E get(int index) {
		if (index < 0 || index >= this.length) {
			throw new IndexOutOfBoundsException();
		}
		return this.data[index];
	}

	/**
	 * adds an element to our array
	 *
	 * @param elem
	 *            element to add
	 */
	public void add(E elem) {
		if (this.cur >= this.length) {
			throw new IndexOutOfBoundsException();
		}
		this.data[cur] = elem;
		this.setCur();
	}

	/**
	 * overloads other add function, allows to add at index
	 *
	 * @param elem
	 *            element to add
	 * @param index
	 *            index at which to add
	 */
	public void add(E elem, int index) {
		if (index < 0 || index >= this.length) {
			throw new IllegalArgumentException();
		}
		if (this.cur == this.length) {
			System.out.println("Array overflow!");
			throw new IllegalArgumentException();
		}
		if (this.data[index] != null) {
			for (int i = index + 1; i < this.length; i++) {
				this.data[i] = this.data[i - 1];
			}
		}
		this.setCur();
		this.data[index] = elem;
	}

	/**
	 * removes item at given index
	 *
	 * @param index
	 *            index at which to remove item
	 * @return item that was removed
	 */
	public E remove(int index) {
		if (index < 0 || index >= this.length) {
			throw new IllegalArgumentException();
		}
		E item = this.data[index];
		if (index == this.length - 1) {
			this.data[index] = null;
			return item;
		}
		for (int i = index; i < this.length - 1; i++) {
			this.data[i] = this.data[i + 1];
		}
		this.setCur();
		return item;
	}

	/**
	 * toString function for our array
	 *
	 * @return string representation of the array
	 */
	public String toString() {
		String out = "";
		out += "[ ";
		for (int i = 0; i < this.length; i++) {
			if (this.get(i) == null) {
				out += "null ";
			} else {
				out += this.get(i) + " ";
			}
		}
		out += "]";
		return out;
	}

	public static void main(String[] args) {
		MyArray<String> s = new MyArray<String>(5);
		s.add("Hello");
		s.add("Shalom");
		s.add("Hola");
		s.add("Bonjour");
		System.out.println(s);
		s.remove(1);
		System.out.println(s);
		s.add("Salaam", 4);
		System.out.println(s);
		s.add("Namaste");
		System.out.println(s);

		MyArray<Node<Boolean>> evens = new MyArray<Node<Boolean>>(10);
		for (int i = 0; i < 10; i++) {
			evens.add(new Node<Boolean>(i % 2 == 0, i));
		}
		System.out.println(evens);
	}
}