Download Lecture 2: Built-In Types of Data

Welcome to CSE 131
This is a very short exercise that you do as part of Lab 0
Review the following slides to learn the anatomy of a Java class
program. There is an exercise for you to complete as part of Lab 0
to test your knowledge of these slides. You can repeat the exercise
as many times as you need until you are able to recognize the
different parts of a Java program.
Anatomy of a Java program
•A Java program can have many packages.
•Each package contains a set of related classes.
•For example, a baseball package might have a Pitcher, Batter, and
Scorekeeper class
•The name of this package is lab0
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Anatomy of a Java program
•A class describes the behaviors of an object.
•This class is called RobotInstructions
•It has just one kind of behavior which is to act
•Other objects have more behaviors
•For example, a Pitcher might throw a ball, catch a ball, etc.
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Anatomy of a Java program
•The behaviors in a class are divided into methods
•This method is named “act”
•A Pitcher might have a method to throw a ball, catch a ball, etc.
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Anatomy of a Java program
•For a method to do its job, it sometimes needs information
•You see here an “incoming parameter” – a “robot” that is provided to
the “act” method.
•The act method can then issue instructions to the robot
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Anatomy of a Java program
•This line of code sends a message to an object to tell it to do
something
•The object here is “robot” – it is the thing we are telling to do
something
•The method call is “forward” – we are asking the robot to go forward
•This method call requires some information – how far forward should
it go?
•The value of 100 is the outgoing parameter, sent to the forward
method, addressed to the robot.
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