MIDTERM_01 - programarejava

MIDTERM 1. Examine the following code. What are the variables?



args



n (*)



i (*)



t

2. In Java, which symbol is used to assign one value to another? 

<



>



= (*)



//

3. Alice uses built-in math operators; they are: 

Add and subtract



Multiply and divide



All of the above (*)



None of the above

4. In Alice, functions are dragged into the control statement, not the procedure. True or false? True False (*)

5. From your Alice lessons, where should comments be placed? 

Above each set of programming statements. (*)



At the end of the program.



In the scene editor.



In their own procedure.

6. An Alice object can move in four directions. True or false? True

False (*)

7. From your Alice lessons, comments do not affect the functionality or behavior of objects. True or false? True (*) False 8. In Alice, inheritance means that the superclass inherits its traits from the subclass. True or false? True False (*) 9. In Alice, declaring a new procedure to shorten code and make it easier to read is a procedural abstraction technique. True or false True (*)

False

10. In Alice, a person object inherits its procedures, functions, and properties from which of the following classes  Object subclass 

Biped class (*)



Quadruped class



Person subclass (*)

11. A scenario gives the Alice animation a purpose. True or false True (*) False 12. From your Alice lessons, random numbers are set in the distance and duration arguments in a procedure. True or false True (*) False

13. In Alice, which of the following instructions turn the Blue Tang fish right one half of a meter? 

this.blueTang turn Right 5



this.blueTang turn Right 0.5 (*)



blueTang turn Right 5



blueTang turn Right 0.5

14. The move procedure moves an object in how many different possible directions 

1



4



3



6 (*)

15. A loop can be infinite (continue forever) or conditional (stops upon a condition). True or false? True (*) False 16. In Alice, we use the While control statement to implement the conditional loop. True or false? True (*) False 17. A conditional loop is a loop that will continue forever. True or false? True False (*) 18. The value that a variable holds must be a whole number, not a decimal. True or false? True False (*) 19. From your Alice lessons, what can be used as a guideline to ensure your animation fulfills animation principles  The Internet 

Animation checklist (*)



A close friend



None of the above

20. An Alice event is considered what? 

A party with at least 20 people



An object's orientation



Error handling

 A keystroke or mouse click (*) 21. Besides invoking a procedure, another way to precisely position an Alice object is to enter values in the x, y, and z coordinates in the Position property. True or false True (*) False

22. From your Alice lessons, what is a one-shot procedural method? 

A procedure that is invoked when the Run button is clicked.



A procedure that is used to make a scene adjustment. (*)



A procedure that is dragged into the code editor.



A procedure that is used to launch the program.

23. From your Alice lessons, how do you add an instance to a scene in Alice?  Select the instance from your computer's network. 

Write code that places the instance in the scene.



Select the class, then drag the object into the scene. (*)



Call the addObject method.

24. When you want specific code to be executed only if certain conditions are met, what type of Java construct would you use  while loop 

if (*)



array



boolean

25. What do lines 7, 10 and 13 do in the following code?



Export files called A, B, and num3.



Create a single file containing A, B, and the value of num3.



Print "A", "B" and the value of num3 on the screen. (*)



None of the above.

26. From your Greenfoot lessons, abstraction techniques can only be used once in a class's source code. True or false? True False (*) 27. From your Greenfoot lessons, which of the following are examples of abstraction? 

Playing a range of sounds when keyboard keys are pressed. (*)



A single instance displays a single image.



Assigning a different keyboard key to each instance. (*)



Programming a single movement for a single instance.



Assigning a different image file to each instance. (*)

28. In Greenfoot, a constructor has a void return type. True or false True False (*) 29. From your Greenfoot lessons, what is the parameter of the following constructor that creates a new image, and designates it to the Actor class? setImage (new GreenfootImage("duke100.png 

setImage



GreenfootImage



duke100.png (*)



new

30. Use your Greenfoot knowledge to answer the question: Where are defined variables typically entered in a class's source code  In the defined method in the source code. 

Between the constructors and methods in the source code.



After the constructors and methods in the source code.

 At the top of the source code, before the constructors and methods. (*) 31. In Greenfoot, a variable can be saved and accessed later, even if the instance no longer exists. True or false ? True False (*) 32. From your Greenfoot lessons, when a method needs additional data to perform a task, this data comes from parameters. True or false? True (*) False 33. In the Greenfoot IDE, which type of variable allows instances to store information 

Method variable



Instance variable (*)



Class variable



World variable

34. From your Greenfoot lessons, how do you call a defined method?  Call the method from the act method. (*) 

Call the method from the defined method.



Write the method in the World superclass.



Write the method in the instance.



Write the method in the source code.

35. To execute a method in your Greenfoot game, where is it called from?  The world 

The act method (*)



The actor class



The gallery

36. From your Greenfoot lessons, to save space in the act method, you can write an entirely new method below it, called a _____________.  Class method 

Instance method



Defined method (*)



World method



Code method

37. Which method is used to play sound in your Greenfoot game 

getSound method



findSound method



playSound method (*)



importSound method

38. In Greenfoot, which method checks if a key on the keyboard has been pressed  keyPress method 

keyUp method



keyDown method (*)



keyClick method

39. In the Greenfoot IDE, what symbols indicate that the variable is an array?  Square brackets [ ] (*) 

Curly brackets { }



Semicolon ;



Colon :

40. In Greenfoot, which of the following statements could prevent an infinite loop from occurring?  I = 100 + i 

i=1



i=i



i = i + 1 (*)

41. In Greenfoot, what happens if the end to a while loop isn't established?  The code will keep executing and will never stop. (*) 

The code will execute once and then stop, due to controls in Greenfoot.



The code will prompt you to enter a loop counter.



The code will not execute.

42. In Greenfoot, in which programming task are the objects identified  Define the problem.



Design the solution.



Program the solution. (*)



Test the solution.

43. Use your Greenfoot skills to answer the question. What is incorrect in this code?



Spacing missing



Curly brace missing



Parenthesis missing (*)



Comma missing

44. From your Greenfoot lessons, a problem statement defines the purpose for your game. True or false True (*) False 45. From your Greenfoot lessons, where do you review a class's inherited methods 

Act method



Documentation (*)



Inspector



If-statement

46. From your Greenfoot lessons, the reset button resets the scenario back to its initial position. True or false? True (*)

False

47. Which of the following Java syntax is used to correctly create a Duke subclass 

private Dog extends World



public class Dog extends World



public class Duke extends Animal (*)



private class extends Actor



private class extends Duke

48. When a Greenfoot code segment is executed in an if-statement, each line of code is executed in sequential order. True or false? True (*) False 49. In a Greenfoot if-else statement, if the condition is true, the if-statement is executed, and then the else-statement is executed. True or false True False (*)

50. Read the following method signature. Using your Greenfoot experience, what does this method do? public static int getRandomNumber (int limit)  Returns a random number less than 10. 

Returns a random coordinate position in the world.



Returns a random number between zero and parameter limit. (*)



Returns a random number for instances in the animal class only.