About Question enthuware.ocpjp.v7.2.1490 :

[sinapse]

"You want to disable assertions for all classes of bad.* as well as good.* but at the same time want to enable them for Main.class."

With this:

java -ea:... -da:good... -da:bad... Main

You are enable assertion for the whole default package, which is different from what you were asking . ?

[tn1408]

#4 is correct.
However could #1 be correct also?
Because assertion is by default disabled so we don't have to do anything to packages good and bad. All we have to do is enable assertion for main. Which is #1: java -ea Main

Thanks

Tony,

[admin]

If you just do -ea without specifying any package or class using the colon syntax, assertions will be enabled for all. That is my #1 is wrong.

[SepticInsect]

I agree with @sinapse
Shouldn't the correct answer be

Code: Select all

java -ea:Main -da:good... -da:bad... Main

[admin]

I agree with @sinapse
Shouldn't the correct answer be

Code: Select all

java -ea:Main -da:good... -da:bad... Main

Yes, this can do the job as well. But the question doesn't ask you to disable assertions for the default package. Neither does it asks you to enable assertions for ONLY for Main.class. So the given solution works as well.

HTH,
Paul.

[ewebxml]

Is the * for option b) invalid syntax for assertions?

java -ea:* -da:good.* -da:bad.* Main


Please confirm.

[admin]

What happened when you tried it out?

[ewebxml]

Code: Select all

/*  
I placed this code into C:\java.
When you run this code from the command prompt using
C:\java>java -ea: AssertionTest
it will print 	
done
*/

public class AssertionTest {
 public static int y;
 public static int foo(int x) {
  System.out.print("foo");
  return y = x;
 }
 public static int bar(int z) {
  System.out.print("bar");
  return y = z;
 }

 public static void main(String[] args) {
  int t = 2;
  assert t < 4 : bar(7); 	
  assert t > 1 : foo(8); 
  System.out.print("done");
 }
}

I compiled and ran the above code from a C:\java> directory

Did it again using

C:\java>java -ea:* -da:good.* -da:bad.* AssertionTest
done
C:\java>


Oracle Docs has no mention of * "Asterisk" in notation.
Is this to throw the test taker off or is it actually used somewhere?

Please clarify.

http://docs.oracle.com/cd/E19683-01/806 ... index.html

[admin]

-ea:* is not valid usage. Yes, -ea:* doesn't generate any error but it doesn't enable assertions for Main either. That is why this is an incorrect option.

HTH,
Paul.

[insider]

The explanation states that "Each enable or disable modifies the one before it."
Does it imply having some kind of order involved? It doesn't seem so.

Consider having a runnable (main) class with "assert false;" as the only line.
"-ea", "-ea:com.Test -da" and "-da -ea:com.Test" all result in AssertionError.

[admin]

As per Oracle's Assertion tutorial

If a single command line contains multiple instances of these switches, they are processed in order before loading any classes. For example, the following command runs the BatTutor program with assertions enabled in package com.wombat.fruitbat but disabled in class com.wombat.fruitbat.Brickbat:

java -ea:com.wombat.fruitbat... -da:com.wombat.fruitbat.Brickbat BatTutor

So there is some kind of order.
-Paul.

[insider]

But that does not imply that one modifies another?

[admin]

But that does not imply that one modifies another?

You are right. That statement is confusing. Updated.
thank you for your feedback!
Paul.