import java.awt.*;
import java.applet.*;
import java.awt.event.*;

public class ArrayBounds extends Applet implements ActionListener
{
	private double[] price;
	private String[] product;
	private TextField T1,T2,T3,errMess;
	private Label L1, L2, L3, L4;
	private Panel P1,P2;
	private int choice;
	
public ArrayBounds()	//constructor
	{
	
	price = new double[6];		// parallel arrays - ie same index used for both
	product = new String[6];	// so if we get product 5 we also get price 5
	setProducts();					// user-defined methods to fill arrays with data
	setPrices();	
	T1 = new TextField(1);
	T2 = new TextField(10);
	T3 = new TextField(10);
	L1 = new Label("Enter choice 1-6");
	L2 = new Label("Product");
	L3 = new Label ("Price");
	errMess = new TextField(20);
	T1.addActionListener(this);
	T2.addActionListener(this);
	T3.addActionListener(this);
	
	P1 = new Panel();	
	P2 = new Panel(); // for output error message
	P1.add(L1);
	P1.add(T1);
	P1.add(L2);
	P1.add(T2);
	P1.add(L3);
	P1.add(T3);
	add(P1);
	}
public void actionPerformed (ActionEvent ae)
	{
		try
		{
		P2.setVisible(false);
		choice = Integer.parseInt(T1.getText()); // converts text to int
		choice--;									// subtracts 1 because array starts at zero
		T2.setText(product[choice]);
		T3.setText(Double.toString(price[choice]));
		}
		catch (NumberFormatException nf)		
		{
		P2.add(errMess);
		errMess.setText("Invalid choice - type a number");
		add(P2);
		P2.setVisible(true);
		validate();
		}   // end catch
		catch (ArrayIndexOutOfBoundsException e)
		{
		P2.add(errMess);
		errMess.setText("No such product");
		add(P2);
		P2.setVisible(true);
		validate();

		
		} // end catch
	
	
	
	}
	

public void setProducts()			// method definitions
	{
	product[0] = "Eggs ";
	product[1] = "Bacon ";
	product[2] = "Tomatoes ";
	product[3] = "Sausages ";
	product[4] = "Black Pudding ";
	product[5] = "Bread ";
	}
public void setPrices()
	{
	price[0] = 0.85;
	price[1] = 1.87;
	price[2] = 0.66;
	price[3] = 1.25;
	price[4] = 1.33;
	price[5] = 0.65;
	}
	
}