Tricky Class Name..?

[anand phulwani]

can anyone explain me about this...

class test22$abc
{
public test22$abc()
{
System.out.println("Outer");
}
}
public class test22
{


class abc
{
abc()
{
System.out.println("Inner");
}
}

public static void main(String acc[])
{
Class$abc a=new Class$abc();
test22 me=new test22();
test22.abc x=me.new abc();
System.out.println("hI");
}
 
and why doesnt it compiles..?
Error:
 
}
  

test22.java:13: duplicate class: test22.abc
class abc
^
test22.java:25: cannot find symbol
symbol : class abc
location: class test22
test22.abc x=me.new abc();
^
test22.java:25: cannot find symbol
symbol : class abc
location: class test22
test22.abc x=me.new abc();
^
3 errors[CODE]

Thanx

[Jesus Angeles]

above, you defined

class test22$abc{
public test22$abc()
{
System.out.println("Outer");
}}


Your inner class will have exactly same name, so its a duplicate. test22$abc will be the compiled name of the inner class.

[anand phulwani]

HI, thanx for you reply

but could you please elaborate watz going on behind the scenes..

thanx

[Jesus Angeles]

as you already probably know,

the inner class is compiled into its very own class file

its name is Outerclassname plus '$' plus Innerclassname plus '.class'

so in your case, your inner class will be compiled to test22+$+abc+.class

ending up as test22$abc.class

exactly same as your other class

so its a duplicate

[Barry Gaunt]

From the Java Language Specification (JLS) 3rd Edition: "The $ character should be used only in mechanically generated source code or, rarely, to access preexisting names on legacy systems."

The Java compiler generates nested class names containing $, so programmers should definitely avoid using it in class names. Within string literals or as a character to be input, processed, and output, the appearance of '$' is perfectly normal.