"Thinking in Java 4th Edition" Reading notes 1.1 abstract process

Q: What is Object-oriented? What is the difference from a process-oriented one?

A: Object-oriented: The problem-oriented space, based on the abstraction of the problem;

Process oriented: The solution space, based on the computer structure to abstract;

Five basic features of OOP:

1) All things are objects.

Explain

You can extract any conceptualization artifacts that you want to solve for a problem and represent them as objects in your program.

2) programs are collections of objects that they communicate to each other by sending messages.

Explain

That is, a request for a method of a particular object.

3) Each object has its own storage composed of other objects.

Explain

You can create new types of objects by creating a package that contains existing objects, so you can build complex systems in your programs, and colleagues hide their complexity behind the simplicity of the object.

4) Each object has its type.

Explain

Each object is an instance of a class (instance).

5) A particular type of even object can accept the same message.

Explain

Objects of the "circle" type are also objects of type "geometry", so the "circle" object must be able to accept messages sent to the Geometry object. This means that the "geometry" interacts and automatically handles all the code related to the geometry. This alternative (substitutablility) is one of the most powerful concepts in OOP (inheritance).

"Thinking in Java 4th Edition" Reading notes 1.1 abstract process