abstract class

[Mathew Lee]

// located in the East end
package spital;

abstract class Spital{
public Spital(int i){}
}
public class Mudchute extends Spital{
    public static void main(String argv[]){

    Mudchute ms = new Mudchute();
    ms.go();
    }
    public  Mudchute(){
    super(10);
    }
    public void go(){
    island();

    }
    public void island(){
    System.out.println("island");
    }

}

1) Compile time error, any package declaration must appear before anything else
2) Output of 10 followed by island
3) Output of 10 followed by "spital island"
4) Compile time error






I was reading above question from link

http://www.jchq.net/certkey/0401certkey.htm
did not understand it clearly. can there be abstract class without abstract methods.


Any ideas, resources,sample code,links, highly appreciated. thanks in advance.

[Campbell Ritchie]

public abstract class Foo{}

Try it; it will compile. Not that you can do a lot with it An abstract class might have no abstract methods.

Is question 4 supposed to say "Runtime error?" That would of course mean an Exception.

The correct answer to your question is "none of the above". I suggest you need a pencil and paper and go through the execution and work out what it will really print.

[Frankely Diaz]

2) Output of 10 followed by island

that's the correct answer there is not errors or problems in your code

Yes, there will be an abstract class without abstract methods.
What you can not have is an abstract method in a non-abstract class.

[Campbell Ritchie]

Frankely Diaz wrote:2) Output of 10 followed by island

that's the correct answer there is not errors or problems in your code . . .

Disagree. You don't get that output. Not with the code which has been posted.

[Frankely Diaz]

Campbell Ritchie wrote:

Frankely Diaz wrote:2) Output of 10 followed by island

that's the correct answer there is not errors or problems in your code . . .

Disagree. You don't get that output. Not with the code which has been posted.

Why, where it goes wrong?

[Paul Clapham]

Frankely Diaz wrote:

Campbell Ritchie wrote:

Frankely Diaz wrote:2) Output of 10 followed by island

that's the correct answer there is not errors or problems in your code . . .

Disagree. You don't get that output. Not with the code which has been posted.

Why, where it goes wrong?

You say it outputs 10, then it outputs "island"? Then it's up to you to explain how those two things happen.
[Edit]Corrected spelling of "say"[/edit. CR]

[Rahul Sudip Bose]

compiles but produces this runtime error : Why ?

Exception in thread "main" java.lang.NoClassDefFoundError: Mudchute (wrong name: spital/Mudchute)
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClassCond(Unknown Source)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$000(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: Mudchute.  Program will exit.

[Campbell Ritchie]

Because you are not using the package name. It's not

java Mudchuite

but

java spital.Mudchute

[Rahul Sudip Bose]

Campbell Ritchie wrote:Because you are not using the package name. It's not

java Mudchuite

but

java spital.Mudchute

did that, still the same error ?

[Sudhakar Sharma]

Rahul Sudip Bose wrote:

Campbell Ritchie wrote:Because you are not using the package name. It's not

java Mudchuite

but

java spital.Mudchute

did that, still the same error ?

may be you are inside the spital directory.

[Rahul Sudip Bose]

Sudhakar Sharma wrote:
may be you are inside the spital directory.

Thanks
i made spital directory/package and compiled the code there. ran "spital.Mudchute" from one directory above spital , it runs

output is :
island

[Frankely Diaz]

Paul Clapham wrote:

Frankely Diaz wrote:

Campbell Ritchie wrote:

Frankely Diaz wrote:2) Output of 10 followed by island

that's the correct answer there is not errors or problems in your code . . .

Disagree. You don't get that output. Not with the code which has been posted.

Why, where it goes wrong?

You say it outputs 10, then it outputs "island"? Then it's up to you to explain how those two things happen.
[Edit]Corrected spelling of "say"[/edit. CR]

I just took the correct answer of those options , assuming that the class was in the correct directory and was called with the full qualified name. Or i got wrong?

[Joanne Neal]

Frankely Diaz wrote:

Paul Clapham wrote:You say it outputs 10, then it outputs "island"? Then it's up to you to explain how those two things happen.

I just took the correct answer of those options , assuming that the class was in the correct directory and was called with the full qualified name. Or i got wrong?

Can you tell us which line of the code prints "10" ?

[Frankely Diaz]

Joanne Neal wrote:

Frankely Diaz wrote:

Paul Clapham wrote:You say it outputs 10, then it outputs "island"? Then it's up to you to explain how those two things happen.

I just took the correct answer of those options , assuming that the class was in the correct directory and was called with the full qualified name. Or i got wrong?

Can you tell us which line of the code prints "10" ?

really scrub U_U did not read the 10 in the sentence, sorry hehe

[Campbell Ritchie]

Just shows you have to read the question

[Frankely Diaz]

Campbell Ritchie wrote:Just shows you have to read the question

Yes, newbie errors u_u