| Question | Answer |
| What is a data type? | All data in Alice MUST be categorized based on the kind of data it represents. So variables, parameters, and functions must have a data type. Examples of data types are number, boolean, string, object, direction, etc. |
| What is the “wait” statement? | The wait statement is located on the bottom of the code editor, next to the Do in order and Do together constructs. It is used to add a pause in your animation. If you want to make your program pause for a few seconds between 2 lines add a wait statement. |
| How does an If/Else statement work? | It evaluates a condition and based on the value, it executes code. So if the condition is True, then it will execute the code in the first block (under the If line). If it is False, it will execute the code in the “Else” block. |
| What is the “print” statement? | The print statement is located on the bottom of the code editor, next to the Do in order and Do together constructs. It is used to print phrases or even the values of variables in your program right onto the screen during the runtime of the animation. |
| What is a Property? | Properties are the characteristics of the object, such as color, opacity. You can change the properties during scene setup and runtime. For example, “cookie set vehicle to tortoise”. |
| What is an event-handling method? | It is the method that you call when an event occurs. Example “shootBolt” was the method that we called to handle mouse clicks in the Zeus lab. |
| How should we name methods, properties, functions, variables, and parameters? | Using camel case, and with NO spaces!!! Method names should always begin with a verb. Example: moveToTable. Notice how the first letter is lowercase. |
| What is a built-in method? | Built-in methods are the actions that an object can do. So verbs like move, turn, and roll are examples of built-in methods. They are already defined and provided to us to use in Alice. |
| What is a variable? | A variable is a placeholder that can hold a value. You can use that variable in your code as needed, and change its value at any time. An example is “x set value to 5”. Now anytime you refer to x, the computer knows you really mean the number 5. |
| What is a data structure? | A data structure defines a way that you group data together. In Alice, the only data structure that you can use is a “List”. You can use lists, whenever you would like to make similar objects do the same actions. Like a marching band. |
| What is the vehicle property? | It is a property available on all the objects in Alice. It defines what you want your object to move with. For example, if you set a skater’s vehicle to a skateboard, then the skater will go wherever his skateboard goes. |
| What is the indefinite loop in Alice? | The “While” construct is an indefinite loop in Alice since it does NOT specify an exact number of times for the loop to repeat. Instead, it depends on a condition that must evaluate to True in order to run the code inside it. |
| How can you iterate through a list in Alice? | You can use the “For all in order” to make them do the actions one at a time, or “For all together” to make them all do the actions at the same time. |
| What do you have to use in order to make an object move along ANOTHER object’s axis? | “As Seen By” option. |
| What is a conditional statement? | A conditional statement is a code construct that uses a Boolean expression to make a decision. Examples of conditional statements are “If/Else” and “While”. |
| What is a parameter? | It is a value you pass to a method (or function) in order to be used in the method’s code. It allows your method to be more flexible and applicable to multiple scenarios. For example, iceSkater.skate(10) will make the skater go 10 meters. |
| In which kind of motion do the 3 axes of an object change with its movement? | In rotational motion! Remember the “ball rolling” lab? The “forward” axis was changing as the ball was turning, which messed up the rolling. |
| What is a repetitive construct? | Whenever you have an action that needs to be repeated a certain number of times, you can use a repetitive construct to accomplish that. In every programming language, there are two types of repetitive constructs: definite and indefinite. |
| How can you control the visibility of an object in Alice? | Using “isShowing” (true/false) or “opacity” (number from 0 to 1). |
| How are object names spelled? | Objects are always NOT capitalized, but “camel cased”, example “boy”, “table”, “airplane”, “toySoldier”, etc. |
| What do we mean when we say a class is an “abstract” definition? | “Abstract” means “theoretical” or “conceptual”. It is not the actual object that you can control with your code; it just defines what an object of this class will look like, its properties and methods and functions will be once used in an Alice world. |
| What is an object? | An object is created in the Alice world, when you drag and drop a Class in the world. It is the actual instance of that class that can be used in your animation. You use properties, methods, functions provided to manipulate your object. |
| What code construct do we use in Alice to make a decision? | The If/Else statement. |
| How are class names spelled? | Classes are always capitalized, example “Boy”, “Table”, “Airplane”, “ToySoldier”, etc. |
| What is a gallery? | The collection of all the classes provided in Alice. For example, the People gallery contains all the classes of people, such as Girl, Boy, Coach, IceSkater, etc. The Animals gallery contains all the classes of animals, such as Cat, Dog, Mouse, etc. |
| What is Interactive Programming? | Interactive programs allow the user to provide input during the runtime of an animation. The program responds to the user’s input with specific behavior defined in an event-handling method. Examples of input from user are “mouse clicks” and “key strokes”. |
| What is a Code Construct? (also known as control structure) | It is a block of code with a specific format and function. For example, “Do together”, or ”Do in order”, or “If/Else”, or “Loop”, etc. |
| What is the virtual world in Alice? | The frame where you can put your objects and create your animation in Alice. It is a 3D world, where objects have 3 dimensions: width, height and depth. |
| What is rotational motion? | It is when an object moves (rotates) around its own center. It does not move with respect to the world – it stays in place. Examples are roll, turn, turn to face, etc… |
| What is the main difference between a method and a function? | Methods are used to define new “ACTIONS” for the object, but functions are used to calculate new values about the object and return that value back to the function call in order to use it in your code. |
| What are the 2 views that you can use during scene setup? | Single view (the current view of the camera) versus Quad View (shows you the camera view as well as view from the top, the right, and front). |
| What is a global variable? | It is a variable that you create on the World “properties” tab in Alice. This variable will be accessible and updatable by ANY method in your Alice project, regardless if it is on the world level or on a class level. That is why it is called “global”. |
| What is a local variable? | In contrast to a global variable, a local variable is defined inside a specific method or function. So it will only be accessible and updatable inside that one method of function. |
| How many times does an If statement run? | ONCE! |
| Can you create your own methods and functions? | YES! |
| What is the definite loop in Alice? | It is the “Loop” construct. It specifies exactly how many times should the loop repeat. Example: “Loop 10 times” will make the code inside it repeat exactly 10 times. |
| What is translational motion? | It is when an object moves with respect to the world. So this motion changes the object’s position in the world. Example, move, move to, move towards, etc… |
| What is a built-in Function? | Functions do NOT correspond to actions; instead they calculate a value and return it back so we can use that value in our code as needed. Examples are “distance to”, “is smaller than”, “width”, “height”, etc. |
| What do we mean when we say an object is “concrete” or “real”? | “Concrete” / “real” means “actual”. It is the actual object found in your Alice world and you can control with your code. |
| What is a Class? | It is a specific type of object defined in the Gallery. Each class definition defines the properties, methods and functions available for the class. |
| What are comments? | Comments are located on the bottom of the code editor. It looks like “//”. Comments are simply notes that the programmer writes in the program to explain/remind the reader what the code is really doing. They are NOT executable code. |
