The Fission Theory: This theory proposes that the Moon was once part of the Earth and somehow separated from the Earth early in the history of the solar system.
This provides modular approach to programming. Classes. A class is a concept used in object oriented programming languages such as C++, PHP, and JAVA etc. Apart from holding data, a class is also used to hold functions. An object is an instant of a class. In case of variables, the type is the class whereas the variable is the object.
That would give you the Class object of the class representing the A.class object which is again an instance of java.lang.Class. They are actually different with regards to where you can use them. A.class works at compile time while a.getClass() requires an instance of type A and works at runtime. There may be a performance difference as well. While A.class can be resolved by the compiler because it knows the actual type of A, a.getClass() is a virtual method call happening at runtime. For reference, a compiler targeting bytecode typically emits the following instructions for Integer.getClass():