head first java chapter 2

This chapter helped me understand the basics of Object Oriented Programming (OOP). I really like the concept of OOP, it turns programming to an organized set of classes and objects that can be changed or easily. 

Some other things I learned include:

• main() should only be used to test real classes and/or to launch and start a Java application
• Objects can "communtcate" to teach other by calling methods on each other
• "Global" variables don't really exist in Java OOP, but later we'll learn how usingpublic and static can make a variable behave like a global one
• Subclasses can inherit instance variables and methods from superclasses