Does every program in Java require a class?

Question

Every Java program requires the presence of at least one class.

Is the above statement always true ?

Answer 1

Yes, you need at least one class to have a program, but no, you do not need any methods (contrary to some other answers).

The reason you need a class is because in Java, all code is inside classes. So to have any code, you need a class. However, code doesn't necessarily need to be in a method. It can also be in initializers. So, here is a complete Java program with no methods:

class LookMaNoMethods {
    static {
        System.out.println("Hello, world!");
        System.exit(0);
    }
}

And that gives...

$ javac LookMaNoMethods.java 
$ java LookMaNoMethods 
Hello, world!
$ 

EDIT : From Java 7 the above code with just static block and no main method does not produce any output. Main method is now compulsory. The code with no main method compiles successfully though.