Chapter 9 Class Mechanism

I was a little confused by the method call in FQCN and the instance (attribute, operation) from the class, so I organized it first.

FQCN: package.Class.method()
Method call (Class) on the instance. Let n be the variable of the instance n.method()

// FQCN: Fully Qualified Class Name

class

Instance fields are attribute variables.

Instances are created from fields and operations (methods, actions) defined in the class.

has-a relationship: A relationship in which one class uses another class as a field.

What is a constructor?

A method that is automatically executed immediately after the class is new. public class Hero { int hp; Hero() { this.hp = 100; // Initialize the hp field with 100. } }

"Call another constructor" rule in overload

Write this (argument);.

Class(String names) { this.name = names; this.hp = 100 Class { this("Bob"); }}

Static field

If you add static to the field, it becomes a static field. Accessing a static field from an instance variable also affects the original static field.

[Java] Classes, constructors, static members