Braindump / Ch 2 Beginning Ruby

CH 2: TOUR OF RUBY & OBJECT ORIENTATION

Object

1. an object is a single instance of a class.
2. object is the actual object or “thing” itself.
3. an object of class Person is a single person

Classes

1. a class is the classification
2. the definition of a single type of object
3. starts with a capital letter just like global constants which therefore makes it available as a global constant.

attr in attr_accessor

1. stands for “attribute”

accessor in attr_accessor

1. roughly means “make these attributes accessible to be set and changed.”

Inheritance like Single Table Inheritance

1. hierarchy of classes; and sub/child classes inherits attributes and methods from the parent class
2. can still add class-specific code to sub/child class

Class Method

1. ruby supplies all objects a class by default
2. you can ask any object of which class it’s a member by using its class method, i.e. puts 2.class

Fixnum Class

1. numbers

Kernel & Kernel Methods

1. kernel is a special class(actually, a module) whose methods are made available in every class and scope throughout ruby.

puts

1. is a method made available from the Kernel module

Kernel module

1. a special type of class packed full of standard, commonly used methods, making your code easier to read and write

String Class

1. strings
2. has many methods, examples: capitalize, downcase, chop, hash, next, reverse, sum, or swapcase.

Braindumps from Beginning Ruby

[ Last updated: June 21, 2008 @ 12:34 AM ]