Another error in the book?

[Aaron Kulbe]

I'm not sure if this is the case... but I'm having trouble with the very first set of code in the "Head First Java" book.

----------------------------------------------------
import java.awt.*;

import java.awt.event.*;

class Party {

public void buildInvite() {

Frame f = new Frame();
Label l = new Label("Party at Tim's");
Button b = new Button("You bet");
Button c = new Button("Shoot me")
Panel p = new Panel();
p.add(l);
} // more code...


--------------------------------------------------

that's how I have the code typed out. That's EXACTLY how it appears to me in the book. With the left-out semi-colon on the end of the Button c line, and with an l (el) in the p.add line.

I get compile errors with this, as follows:

bash-2.05b$ javac Party.java
Party.java:12: ';' expected
Button c = new Button("Shoot me")
^
Party.java:15: '}' expected
} // more code...
^
Party.java:10: cannot resolve symbol
symbol : class Level
location: class Party
Label l = new Level("Party at Tim's");
^
Party.java:14: cannot resolve symbol
symbol : variable p
location: class Party
p.add(1);
^
4 errors
bash-2.05b$

That's have it typed out. what gives?

[Sudheer Reddy]

hai,
Don't put book printing mistake errors into Forum.Better u ask any java genuine errors.

[Ernest Friedman-Hill]

Hi Aaron,

Welcome to JavaRanch!

Indeed, this does look like a typo in the book. The best place to discuss book issues is in our Bunkhouse Porch forum. I'm going to move this post there for followup.

Note that this book, like many books, has a web page listing printing errors. It's a good idea to check this list.

[Pauline McNamara]

Now that's a sight, actual *code* on the Bunkhouse Porch.

Looks like there are a few typos in there Aaron, so you probably will find them on the errata list for this book. I'm having trouble locating where that code is exactly in the book (I suspect it's way beyond the very first code), but with the page numbers you should have no problem.

The compiler is crying out to help you fix them too, of course. That missing ; on line 12, then a right curly bracket on line 15 to match the opening class bracket, those are the nice errors (that is, easy to fix ).

The next one confuses me a bit, though. The error says that the compiler is looking for a class called Level, from line 10:

Label l = new Level("Party at Tim's");

Yet the code you give above

Label l = new Label("Party at Tim's"); // Label, not Level

doesn't quite look the same, and probably wouldn't give that error.

....

Anyway, after addding a closing curly bracket and a semicolon, the code as follows compiled fine for me:

import java.awt.*;
 
import java.awt.event.*;
 
class Party {
 
    public void buildInvite() {
 
        Frame f = new Frame();
        Label l = new Label("Party at Tim's");
        Button b = new Button("You bet");
        Button c = new Button("Shoot me") ;
        Panel p = new Panel();
        p.add(l);
    } // more code...
}

Simple compiler errors can induce other, more mysterious ones - fixing those syntax mistakes first sometimes clears up those later errors too.


Like Ernest said, welcome to the ranch and hope you'll be visiting often. And enjoy Head First Java


Pauline
[ June 18, 2004: Message edited by: Pauline McNamara ]