CS 3 - Kurtz  Santa Monica College 






Anything that can be identified as unique from other things
Something you can actually see
Has 6 degrees of freedom (up, down, right, left, back, forward)
Objects have properties and methods associated with them


Computer Program

A way to tell the computer what to do
A list of instructions to accomplish a task
A way to tell another human being what you want the computer to do


List of Instructions


Sequential processing




Conditional execution
A decision is made based on the evaluation of a Boolean expression
The decision determines the flow of execution in a program


Boolean expression

Repeating Behavior


An expression that evaluates to True or False 





A question in a computer program
A method that returns a value




A segment of program code that defines how to perform a specific task
Invoked by calling the method
World-level methods typically involve more than one object
Class-level methods are typically specific to a single object


Object Tree


Contains a list of objects in the current world


Control Statement


Tells Alice how to carry out instructions in a program
e.g., do in order, do together




An item of information that must be supplied to a method so that Alice can execute the action
e.g., object to act upon, distance, direction




A method and its arguments
An action to be performed 




An unambiguous step-by-step sequence of instructions




Writing one program statement inside another


Trial and error strategy 

  e.g., plascing a "Do together" block inside of a "Do in order" block

Attempting several argument values to determine the optimum value
Sometimes useful in conjunction with good planning

Class Contains all of the information necessary to create objects
Objects are considered instances of a class
Objects are instantiated (created) from classes
Each instance of a class is a unique object
Objects instantiated from the same class will all have the same properties and methods, but are different and unique objects
Parameters Used to communicate with methods
Values that are passed to methods when they are called
May be a number, Boolean, object, string, color, texture map, sound, pose, position, orientation, point of view, reference frame, transformable, light, or direction in Alice.