Object-Oriented Programming book (Abstract)

1. Almost no class can exist independently. In most cases, if a class does not interact with other classes, there is no reason to build it.

2. In fact, there is no global data in OO development. Static attributes and methods share all objects in the same class, but objects in other classes cannot be accessed.

3. Do not change the public interface at any cost. If you modify the public interface, all the systems that use this interface will have a ripple effect.

4. To send an object through the network (for example, sending it to a file through the network), the system must expand the object, send it through the network, and then resynthesize it at the other end of the network. This process is called a serializing object. The specific behavior of sending objects through the network becomes an object of packet aling.