Quick question about import and inheretence

[N00Bie]

Hi,
I have two classes, the first is with my main() function and it has this:

import javax.swing.JFrame;
public class GUI {

I have bolded the part that I want to talk about, and my second class has this:

import java.awt.FlowLayout; // gets the flowlayout
import javax.swing.JFrame; // gets the whole pane with the minimize,maximize, x button etc
import javax.swing.JLabel;

public class GUI_Sub extends JFrame{

My question:
How come in the main class I have to import like this "javax.swing.JFrame" but in the second class (which does not have a main() method and gets called by the first class) all I say is " extends JFrame" and thats enough?
Shouldnt it be "extends javax.swing.JFrame"?
How does Java know which "JFrame" I am talking about?


Thanks!

[TheEnemy]

I think you've missed that you also has an import for javax.swing.JFrame in your second class. So it knows you mean javax.swing.JFrame for the extend. If you were to remove that import, you'd have to specify the complete path to JFrame in the extends line.

import java.awt.FlowLayout; // gets the flowlayout
[B]// (removed) import javax.swing.JFrame;[/B] // gets the whole pane with the minimize,maximize, x button etc
import javax.swing.JLabel;

public class GUI_Sub extends [B]javax.swing.JFrame[/B]{

[N00Bie]

Ah! That makes sense! Thanks!
(Also like your sig... so true... so damn true!)

[masijade]

To make it clearer, an import does not "import" anything. It is simply a short-hand for the programmer (and a reference for the compiler) so that the programmer, in the code, does not have to type the entire package path for the classes being referenced.