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.
1 Class methods can access class variables and class methods directly. 2  Class methods cannot access instance variables or instance methods directlythey must use an object reference. 3  Also, class methods cannot use the this keyword as there is no instance for this to refer to.