Error in Sun Certified Programmer for Java 6 Study Guide

[Jim Carney]

page 829, question 11. looks to me like the answer is C, not A. and the explanaition as to why it is not C is confusing me...

anyone else see this?

[Vierda Mila]

Hi Jim,

Kindly to post above question so we can help you in this forum.

regards,
-Vierda Mila-
[ October 13, 2008: Message edited by: Vierda Mila ]

[Graeme Jenkinson]

Question (hopefully copied without any mistakes!)

Given the following directory structure:

test-|
     | - GetJar.java
     |
     | - myApp - |
                 | - Foo.java

And given the contents of GetJar.java and Foo.java:

3. public class GetJar {
4.    public static void main(String[] args) {
5.       System.out.println(Foo.d);
6.    }
7. }
 
3. package myApp;
4. public class Foo {public static int d = 8; }

If the current directory is test, which set(s) of commands will successfully compile the two java files and produce the output 8? (Choose all that apply.)

A. javac myApp/Foo.java
// put into "test" a jar file that contains myApp/Foo.class
javac -classpath MyJar.jar GetJar.java
java GetJar

B. javac myApp/Foo.java
// put into "test" a jar file that contains myApp/Foo.class
javac MyJar.jar GetJar.java
java GetJar

C. javac myApp/Foo.java
// put into "test" a jar file that contains myApp/Foo.class
javac -classpath MyJar.jar GetJar.java
java -classpath MyJar.jar GetJar

D. javac myApp/Foo.java
// put into "test" a jar file that contains myApp/Foo.class
javac MyJar.jar GetJar.java
java -classpath MyJar.jar GetJar

Answer A.

I also have some doubts about this. I don't see howthe invocation of java in A can find the class Foo. Whereas, in C both javac and java can locate the class Foo. I also agree that the "explaination" given is rather inadequate.

thanks,

Graeme
[ October 14, 2008: Message edited by: Graeme Jenkinson ]

[Ankit Garg]

Even C is wrong because it doesn't has the current directory i.e. a "." in the classpath. I have also posted this error, and many others too, but there has been no response from the authors..

[Nidhi Sar]

Ankit Garg wrote:Even C is wrong because it doesn't has the current directory i.e. a "." in the classpath. I have also posted this error, and many others too, but there has been no response from the authors..

This is an old forum topic, but I just came across this problem in the book. Ankit, as you pointed out, the only answer that work is the following. It is not one of the choices:

javac -classpath MyJar.jar GetJar.java
java -classpath .:MyJar.jar GetJar.java

You mentioned "many other errors". Is there anyplace you/someone might have compiled these errors? Since the otherwise excellent K&B book is my current main study material, it would be very helpful to have this compilation to refer to.

Thanks,
Nidhi

[Ankit Garg]

Bert is compiling an errata so look forward to it...

[Chintan B Shah]

I posted this same question about a week back.

This question assumes that you don't have CLASSPATH variable set in your ENVIRONMENT VARIABLES.

Thanks to Daniel for helping me figure this out.
Question No. 11-Chapter 10-Wrong answer


Regards,
Chintan
SCJA 1.0

[Mahtab Alam]

why at compiling a . is not included

i thinnk it should be

javac -classpath .:MyJar.jar GetJar.java
java -classpath .:MyJar.jar GetJar

doesn`t javac requires a . (current directory)