Airplane Reservation

[RiterHeng]

Okay so my assignment is this:

Write a Java Applet as a small airline reservation system. The system has only one airplane with 10 seats: 1 to 5 for first class and 6 to 10 for economy. The applet has two buttons and a text field for boarding pass. If the user clicked the First Class button, a currently availabe first class seat is printed in the boarding pass. If the user clicked the Economy button, a currently available economy seat is printed in the boarding pass. If the user selected section has no available seat, your program should ask if the user is OK with the other section seats. If the user clicked OK, you print the boarding pass of the assigned seat. If the user clicked Cancel, print "Next flight leaves in 3 hours"

	import java.awt.*;
	import java.awt.event.*;
	import javax.swing.*;
	public class Assign7 extends JApplet implements ActionListener
	{
	 
	 JButton firstClassButton, economyClassButton;
	 JTextField displayField;
	 
	 boolean[] seat;
	 
	 int i;
	 
	 public void init()
	 {
	 
	 Container container = getContentPane();
	 container.setLayout(new FlowLayout());
	 
	 firstClassButton = new JButton("First Class");
	 firstClassButton.addActionListener(this);
	 container.add(firstClassButton);
	 
	 economyClassButton = new JButton("Economy");
	 economyClassButton.addActionListener(this);
	 container.add(economyClassButton);
	 
	 displayField = new JTextField(20);
	 displayField.setEditable(false);
	 container.add(displayField);
	 
	 seat = new boolean[11];
	 
	 }
	 
	 public void actionPerformed(ActionEvent actionEvent)
	 {
	 
	 if( actionEvent.getSource() == firstClassButton )
	 {
	 reserve(true);
	 displayField.setText("Seat " + i + " has been reserved");
	 }
	 else if( actionEvent.getSource() == economyClassButton )
	 {
	 reserve(false);
	 displayField.setText("Seat " + i + " has been reserved");
	 }
	 }
	 
	 int reserve(boolean firstClass)
	 {
	 if(firstClass = true)
	 {
	 for(i = 1; i <= 5; i++)
	 {
	 seat[i] = true;
	 }
	 }
	 else if(!firstClass)
	 {
	 for(i = 6; i <= 10; i++)
	 {
	 seat[i] = true;
	 }
	 }
	 return i;
	 }
	}

I seem to have messed up the logic in my head and with what I have right now when running the program, when I click first or economy button, I get "Seat 6 has been reserved".

[jlczuk]

First, format that code so it has indentation so it is easier to read.

Second, look at your for loops. You need to understand what they are doing because they are not doing what you want them to do. When you press either button, you want only ONE reservation right? And you want to be the next unreserved seat right?

Third, firstClass is a boolean, therefore you don't need to use:

if (firstClass)  {
}
else if (!firstClass)  {
}

That's just redundant and a distraction. It's better just to use:

if (firstClass)  {
}
else  {
}

And lastly, you really should not be reusing/sharing the i variable like that. When you use a variable as a loop index, you should never reuse it outside the loop like that. You set a different variable to the index of interest, and in this case, should be returning that from the method.

[RiterHeng]

Yes, I want 1 reserved when I click either button. How would I code that?

[Tolls]

	 if(firstClass = true)
	 {

Though jlczuk is correct that the above should be just if (firstClass), the above is wrong because it will always be true.
That is an assignment '=', not a boolean '==', so firstClass is always true after this line.

That aside, try and do this one at a time.
Have you managed to get working code where there is just the one class of seat?
That's where I'd start.
Then add in the concept of two classes.

[DarrylBurke]

Not an Eclipse question. Moving to New to Java.

db

[jlczuk]

	 if(firstClass = true)
	 {

Though jlczuk is correct that the above should be just if (firstClass), the above is wrong because it will always be true.
That is an assignment '=', not a boolean '==', so firstClass is always true after this line.

That aside, try and do this one at a time.
Have you managed to get working code where there is just the one class of seat?
That's where I'd start.
Then add in the concept of two classes.

That's what I get when I try to do a few quick replies before going to bed! I must have been seeing double! ;-)