[masijade]

dont misunderstand me- one doubt----

im writing this program in single notepad, named case.java,,,, if i compile it i get single .class file, ie. case.class file,,,,

so only one .class file present,,,, how c.class and C.class will overwrite thennn
thanx for replying,,,,

I already answered this for you in your other thread.

You have three class definitions (not classes) in a single java (i.e. source code) file. When this file is compiled, each of the compiled classes created from those class definitions, as they are compiled, will be placed into their own class (i.e. byte code/compiled/binary/however you want to refer to them) file. Therefore, one java source code file and three compiled binary class files.