Packgage problem

[sarvesh dikonda]

I came across a question in which it was stated that, classes within the same package can directly access and change the public instance variables within these classes. So, i decided to just try it out as i wanted to see how exactly it is to be done. Below is the code i implemented -

package dd;

public class Tt{
public String name="ddd";
}

package dd;
import dd.*;
//import  static dd.Tt.name;

public class Tte{
public static void main(String [] args){
System.out.println(dd.Tt.name);
}
}

I get the following error -

C:\Documents and Settings\User\Desktop\dd>javac Tte.java
Tte.java:8: cannot find symbol
symbol  : class Tt
location: package dd
System.out.println(dd.Tt.name);
                     ^
1 error

I'm finding difficult to solve the above error. I know its not that difficult, but need your expert help friends.

I want class Tte to access the String variable 'name' from the class Tt. Both the classes are placed in same package dd. I tried different ways as seen the commented lines in class Tte i.e the import statement but i am not able to understand how to do it. Can someone help me out please!

[Himai Minh]

try this:

import static dd.Tt

and

   System.out.println(name);

See if it compiles.

[sarvesh dikonda]

Himai Minh wrote:try this:

import static dd.Tt

and

   System.out.println(name);

See if it compiles.

On compiling the code with your suggested changes it does not work and gives the error as follows-

C:\Documents and Settings\User\Desktop>javac dd\Tte.java
dd\Tte.java:3: cannot find symbol
symbol: class dd
import  static dd.Tt;
               ^
dd\Tte.java:3: static import only from classes and interfaces
import  static dd.Tt;
^
dd\Tte.java:8: cannot find symbol
symbol  : variable name
location: class dd.Tte
System.out.println(name);
                   ^
3 errors

The changed code as follows -

package dd;

public class Tt{
public String name="ddd";
}

 package dd;
//import dd.*;
import  static dd.Tt;

public class Tte{
public static void main(String [] args){
//name="df";
System.out.println(name);
}}

Kindly help me friends i tried with other ways too and am also looking into the problem.
I have a folder named "dd" in which i have placed the Tt.java and Tte.java source files.
And then i have compiled them as following - C:\Documents and Settings\User\Desktop>javac dd\Tt.java // compiles properly
C:\Documents and Settings\User\Desktop>javac dd\Tte.java // on compiling it shows 3 errors as shown above

From the above as you can see, i am compiling from my current directory-> Desktop
Am i compiling correctly , please correct me if i am wrong

[sarvesh dikonda]

Kindly help me with this problem Ranhers! I need to know how this thing goes on to work

[Kancharla Madhu]

Your trying to access instance variable without actual object instance so Compilation Error! i.e

System.out.println(dd.Tt.name);

Do one of the following things.

1) Declare variable, name as static i.e.

 public static String name="ddd";

2) Create Object instance and then invoke the variable name. i.e.

dd.Tt tt = new dd.Tt();
	System.out.println(tt.name);  

[sarvesh dikonda]

Kancharla Madhu wrote:Your trying to access instance variable without actual object instance so Compilation Error! i.e

System.out.println(dd.Tt.name);

Do one of the following things.

1) Declare variable, name as static i.e.

 public static String name="ddd";

2) Create Object instance and then invoke the variable name. i.e.

dd.Tt tt = new dd.Tt();
	System.out.println(tt.name);  

Thank you so much Madhu for your solution . Actually, i knew the first solution that you suggested with 'static' keyword but not about the second one. Thanks. Would you like to give some tips for the OCPJP certification exam.

[Guy Buyle]

Hi,

I think your problem is more related to the javac line command:
I have tried the following:

your sources in: dd

package dd;  
      
    public class Tt{  
    public String name="ddd";  
    }

package dd;  
 import dd.*;  
 //import  static dd.Tt.name;  
  
 public class Tre{  
   public static void main(String [] args){  
   System.out.println(dd.Tt.name);  
 }  
} 

When I compile your sources wth the following command line:

javac -d dd/classes dd/Tt.java
javac -d dd/classes -classpath dd/classes dd/Tre.java

the class Tt compiles fine, no compilation errors but the second compilation line get the following error:

dd\Tre.java:7: non-static variable name cannot be referenced from a static context
      System.out.println(dd.Tt.name);
                                        ^
1 error

I think this is the correct answer on your question.

Regards,
Guy

[John Jai]

Hi GuyB,

Welcome to Javaranch

I have edited your post to have Code Tags in them to make it easily readable. Check how to use them here