master exam question?

[jayalakshmi charugundla]

Hi all,

The below program is absolutely correct. Its output is 30.My doubt is we know that we cann't change the value of final variable.If we tries, it would give compiler error.
I need clarification
please explain this if you know

given two files.
-----------------
package xcom;
public class Stuff {
public static final int MY_CONSTANT=5;
public static int doStuff(int x)
{return (x++)*x;};

}


import xcom.Stuff.*;
import static java.lang.System.out;
class User extends Stuff{
public static void main(String[]a){
new User().go();
}
void go(){out.println(doStuff(MY_CONSTANT));}
}


}

[zheng li]

jayalakshmi charugundla wrote:Hi all,

The below program is absolutely correct. Its output is 30.My doubt is we know that we cann't change the value of final variable.If we tries, it would give compiler error.
I need clarification
please explain this if you know

given two files.
-----------------
package xcom;
public class Stuff {
public static final int MY_CONSTANT=5;
public static int doStuff(int x)
{return (x++)*x;};

}


import xcom.Stuff.*;
import static java.lang.System.out;
class User extends Stuff{
public static void main(String[]a){
new User().go();
}
void go(){out.println(doStuff(MY_CONSTANT));}
}


}

java uses pass-by-value to pass parameters to a method.
x is not MY_CONSTANT, but a copy of it.

if you add keyword final to x, then compilation fails

public static int doStuff(final int x)
{return (x++)*x;}; 

[Ankit Garg]

jayalakshmi please Use Code Tags when you post a source code. That way your code looks formatted. Unformatted code is hard to read. You can add code tags by wrapping your code in [code] [/code] tags. You can edit your message using button and then add code tags to it...

[jayalakshmi charugundla]

Thank you for your explanation.

I forgot to put them in code tags.

[Ankur kothari]

hey did you buy the voucher?

[jayalakshmi charugundla]

yes I bought it yesterday itself.

[Nidhi Sar]

Hi all,

The below program is absolutely correct.

Jayalakshmi,

I am a little confused. Probably there is a typo here. The program, as it stands, does not compile for me.

I think you need to change:
import.Stuff.*;

to one of the following:

import xcom.Stuff;
OR
import xcom.*;

Small difference, but important I guess!