(Computer Studies) Final Exam-
Questions and Answers Graded A+
What is a computer? - ANSWER-A computer is a device that follows instructions for manipulating and storing information.
What is a program? - ANSWER-A computer program is a set of instructions that the computer follows to perform a task.
What is an algorithm? - ANSWER-An algorithm is a set of well-defined logical steps that must be taken in order to perform a task.
What is the only language the computers understand? - ANSWER-Machine language is the only language that computers understand.
Why were programming languages invented? - ANSWER-Because computers only understand machine language (which consists of binary numbers), programming languages were invented to make programming easier. Programming languages consist of words, which are easier for people to understand.
How do you control the speed at which a world is played? - ANSWER-You use the speed slider control on the World Running...window.
What part of the Alice environment displays a view of the world, as seen through the camera? - ANSWER-The World View window.
What part of the Alice environment displays a list of objects in the world? - ANSWER-The Object Tree.
What is a tile? What purpose of tiles did we discuss in this section? - ANSWER-A tile is simply a small rectangular icon. In this section we discussed the use of tiles to represent objects in the Object
Tree.
What are properties? - ANSWER-Properties are values that specify an object's characteristics.
What is the name of the property that determines whether you can see through an object? - ANSWER-The color property determines an object's color. The opacity property determines whether you can see through an object.
What is a method? - ANSWER-A method is a set of programming statements that an object can execute.
Give an example of how an object can be made up of other objects. - ANSWER-An example is the snowman object that we discussed in the snowLove world. The snowman object is made of a head section object, a middle section object, and a bottom section object.
What is a class? - ANSWER-A class is a description of a particular type of object.
How are a class and instances of the class similar to a blueprint and houses built from the blueprint?
- ANSWER-A class is similar to a blueprint, and instances of the class are similar to houses built from the blueprint. The blueprint itself is not a house, but it is a detailed description of a house. When we use the blueprint to build an actual house, we can say that we are building an instance of the house that is described by the blueprint. If we want, we can build several identical houses from the same blueprint, Each house is a separate instance of the house that is described by the blueprint.
What is stored in the Alice galleries: classes or objects? - ANSWER-Classes are stored in the Alice galleries.
When you click the Add Objects button, what mode does Alice go into? - ANSWER-Alice goes into scene editor mode.
After finding the class you want in one of the Alice galleries, describe two ways to add an instance of
the class to the world. - ANSWER-Click the class thumbnail,and then on the information window for the class,click the Add instance to world button. Or click and drag the class thumbnail from the gallery into the world.
What are two ways to select an object in the Alice environment? - ANSWER-Click the object in the World View window. Or click the object's tile in the Object Tree.
What appears around an object in the World View window when you select the object? - ANSWER-A
yellow bounding box appears.
In an Alice world,would the word dog be the name of a class, or the name of an object? How can you tell? - ANSWER-It would be the name of an object because by convention the names of objects began with a lowercase letter and the names of classes begin with an uppercase letter.
In what area of the Alice environment do you select an object's properties? - ANSWER-The Details Panel.
What dimensions do two dimensional objects have? What dimensions do three-dimensional objects have? - ANSWER-Two-dimensional objects have height and width;three-dimensional objects have height, width, and depth.
In what directions may an object in a two-dimensional world move? In what directions may an object in a three-dimensional world move? - ANSWER-An object in a two-dimensional world can move up,down,left,and right;as object in a three-dimensional world can move up, down, left, right, forward, and backward.
What are the seven mouse mode buttons? - ANSWER-Move Freely, Move Up and Down, Turn Left and Right, Turn Forward and Backward, Tumble, Resize, and Copy.
Why would you want to know where an object's center point is before you rotate the object? - ANSWER-Because an object rotates around its center point.
When you select an object you see three axes displayed in the vicinity of the object. These axes indicate the object's orientation. In what direction does each of the axes point? - ANSWER-The green axis points in the object's up direction, the blue axis points in the object's forward direction, and the magenta axis points in the object's right direction.
What four views do you see when in quad view mode? - ANSWER-World View, Top,Right, and Front. Which mouse mode button is not displayed when in quad view mode? Why is the button not displayed? - ANSWER-The Move Up and Down button is not displayed in quad view mode because the right and front viewing windows support up and down movement. If you want to move an object up or down while in quad view mode, simply select the Move Objects Freely button and then move the object up or down in the right view or the front view.
In a three-dimensional system,what do the numbers in a coordinate such as (5,0,1) indicate? - ANSWER-They indicate a position, using the X,Y, and Z axes. The first number (5) is the X coordinate, the second number (0) is the Y coordinate, and the third number (1) is the Z coordinate.
This is what a computer device does. - ANSWER-Follows instructions to perform a task.
This is a set of instructions that the computer follows. - ANSWER-Program
This is a set of well-defined logical steps that must be taken in order to perform a task. - ANSWER-
Algorithm
This is the only language that a computer understands. - ANSWER-Machine Language
This is a number that consists of only 1s and 0s. - ANSWER-Binary
A program written in this is much easier for people to understand than a program written in machine language. - ANSWER-Programming Language
This translates a program into machine language. - ANSWER-Microprocessor
These are the words that make up a programming language. - ANSWER-Keywords
This is a set of rules that must be strictly followed when writing a program. - ANSWER-Syntax
If a program contains even one of these, it cannot be translated into an executable program. - ANSWER-Syntax Error
This is the part of the Alice environment that holds a list of all the objects in the world. - ANSWER-
Object tree
Each object in an Alice world has these, which are values that specify the object's characteristics. - ANSWER-Properties
This is a set of programming statements that an object can execute. - ANSWER-Methods
This is a description of a particular type of object; you can think of it as a blue print that objects may be created from. - ANSWER-Class
In programming terminology, this is what objects are also called. - ANSWER-Instances of a Class
This is a yellow box that appears around an object to indicate that it is selected. - ANSWER-
Bounding Box
This is the part of the Alice environment where an object's properties are displayed. - ANSWER-
Details Panel
This is how many degrees of freedom objects in a 3D world have. - ANSWER-Six This is what an object turns around when you rotate it. - ANSWER-The object's center point.
When an object is selected you see three axes displayed in or near the object, which indicate the object's orientation. This is the direction in which the blue axis points. - ANSWER-Left
What is the World View window and how does it relate to the camera? - ANSWER-The World View window shows a view of the virtual word, acting as the viewfinder of a camera, and provides controls
for moving and rotating the camera.
In Alice, what is a subpart? - ANSWER-Things in Alice are composed of other parts: these are called
subparts. For example, a human character may have two arms and two legs, and these other parts would be the subparts.
In this chapter, blueprints and houses are used as a metaphor. In the metaphor, does a blueprint represent an object or does it represent a class? - ANSWER-In the metaphor of blueprints and houses, a blueprint would represent a class.
Do the Alice galleries contain classes, or actual objects? - ANSWER-The Alice galleries contain classes.
In an Alice world you have an object named hare. The hare object has a method named move. How would you write the method name using dot notation? - ANSWER-hare.move
What causes a method to be executed automatically when a world is played? - ANSWER-The method name is specified in the event tile that reads when the world starts, do.
How do you see a list of the primitive methods that an object has? - ANSWER-First select the object.
Then, in the Details Panel, select the methods tab to display a list of tiles representing the object's methods.
What is a primitive method? Which objects have primitive methods? - ANSWER-A primitive method is a built-in method for performing basic actions. All objects in an Alice world have primitive methods.
When specifying a distance for the move method, what happens when you select other... from the menu? When would you use this selection? - ANSWER-When you select other...the Custom Number keypad appears. You would use this selection when you need to specify a distance that does not appear on the menu.
A fellow classmate has placed an instruction in the Method Editor. You ask her what the method does, and she says, "It calls another method." What does she mean by that? - ANSWER-She means
that it executes another method.
What is an argument? - ANSWER-An argument is any piece of information that a method requires in
order for it to execute.
What is a custom method? Do all classes provide custom methods? - ANSWER-A custom method is
a method that only objects of a specific class have. Not all classes provide custom methods.
How can you see a list of the custom methods that a class has? - ANSWER-If a class provides custom methods, you can see a list of those methods in the class's information window. Also, when you add an instance of the class to the world and then select that object, tiles representing its custom methods (if its has any) appear above the tiles for the primitive methods in the Details Panel.
