Question

Is it possible to create a class within the same file that contains the main method? A programming contest that I’m practicing for only accepts a single file as a solution so I can’t write the class in a separate file and send it in.

I know you can create inner classes but does it provide the same functionality as normal classes?

Answer 1

Yes, you can define multiple top-level classes in a single .java file. See Java: Multiple class declarations in one file

For most purposes nested classes should work just as well. You may want to declare such classes static to avoid the implicit reference to the outer class.