Answer 1

Omerg

Your file name and class name (with main method) should be same.

Answer 2

It working fine... check again.

Answer 3

Where are you trying that?

name file as MyClass.java
Compile first by

javac MyClass.java

Then run by
java MyClass

//if you name other, use same name in compiling but must use main method name while running..
javac jv.java
java MyClass

Answer 4

In general, in java file name must be the same as class name where main() method exist.