CS 3 - Kurtz  Santa Monica College 

ALICE AND OBJECT ORIENTED PROGRAMMING CONCEPTS

 

 

Object

 

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

 

If...then...else 

 

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 

Looping
Iteration

 

Function

 

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

 

Method

 

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

 

Argument

 

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

 

Instruction

 

A method and its arguments
An action to be performed 

 

Algorithm

 

An unambiguous step-by-step sequence of instructions

 

Nesting

 

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.