1. What is the purpose of methods inside a class?

A. To declare new fields B. To perform actions and operate on the object’s data C. To create new classes D. To delete objects

2. Why is using objects considered an abstraction in programming?

A. Because you must know all internal details to use them B. Because it allows you to use objects without knowing internal details C. Because they are difficult to implement D. Because they require no programming knowledge

3. What is a mutator method designed to do?

A. Return the value of an object's field B. Modify the object's internal state C. Display the object's current state D. Create a new instance of a class

4. What is the purpose of an accessor method?

A. To modify the internal state of an object B. To provide read-only access to the object's fields C. To create new instances of a class D. To delete object fields

5. What is the result of `Math.sqrt(x * x + y * y)` in an accessor method in class Point?

A. Distance from the origin to the point `(x, y)` B. The sum of coordinates C. The product of coordinates D. The midpoint of a line

6. Which method type would you use to allow clients read-only access to an object's state?

A. Constructor B. Mutator C. Accessor D. Destructor

7. What keyword is used inside an instance method to refer to the object the method was called on?

A. this B. self C. super D. object

8. In the example method `public void translate(int dx, int dy)`, what kind of method is this?

A. Accessor B. Mutator C. Static method D. Constructor

9. What do instance methods operate on?

A. Static variables B. The class itself C. The particular object on which they are called D. The user input

10. What happens when you call `p1.translate(11, 6)`?

A. It creates a new instance of `p1` B. A method modifies the state of the object `p1` by shifting its coordinates C. It prints the values of `p1` D. It deletes the object `p1`

11. Which statement best describes "object state"?

A. The methods an object can perform B. The data fields associated with the object C. The client's access to the object D. The class's blueprint

12. What is the correct way to call an instance method named `translate` on an object `p1` with parameters 11 and 6?

A. translate(p1, 11, 6); B. p1.translate(11, 6); C. Point.translate(11, 6); D. p1.translate();

13. What is the main purpose of an instance method in a class?

A. To create new classes B. To execute procedural steps C. To operate on particular objects' data D. To store object data fields

14. What is an object in object-oriented programming?

A. A series of procedural steps B. A variable storing only primitive data types C. An entity that combines state and behavior D. A function that performs calculations

15. What distinguishes an object-oriented program from a procedural program?

A. Use of global variables B. Execution order based on user inputs C. Behavior performed as interactions between objects D. Use of subroutines only

16. Which statement correctly creates an instance of a Point class?

A. `Point p1 = Point();` B. `p1 = new Point;` C. `Point p1 = new Point();` D. `new Point p1 = ();`

17. What is the effect of calling a mutator method?

A. It returns information about the object B. It changes the object's internal data C. It throws an error D. It creates a new object

18. Which statement best describes a class in Java?

A. A specific object instance B. A template from which objects are created C. A temporary variable D. A built-in Java method

19. What is procedural programming characterized by?

A. Interactions between objects B. Programs composed as a series of steps to be followed C. Use of classes and objects D. Use of graphical user interfaces

20. When you call an instance method on an object, the object that the method operates on is called the:

A. Static parameter B. Implicit parameter C. Return value D. Local variable

21. How can clients modify an object's fields directly?

A. By calling accessor methods B. By using the syntax `<variable>.<field> = <value>;` C. By calling a class method D. By using private fields only

22. What does this code imply inside an instance method?

A. Assigns 10 to an object’s static variable `x` B. Assigns 10 to the field `x` of the implicit parameter object C. Calls a constructor D. Creates a new object `this` with `x=10`

23. Which statement best describes the role of a client program?

A. It defines new classes B. It modifies the Java language C. It uses objects to accomplish tasks D. It compiles Java code

24. What does the term "client program" refer to in the context of objects?

A. A program that defines objects B. A program that uses objects C. An object that stores data fields D. A class method

25. Why is grouping related variables into an object preferable to declaring them separately?

A. Increases redundancy B. Makes tracking variables easier and organizes data logically C. Decreases encapsulation D. Reduces program efficiency

26. Which of the following best defines an implicit parameter?

A. The first argument passed to a method B. The method’s output C. The object on which an instance method is called D. A hidden variable in the class

27. Which of these is NOT a characteristic of an instance method?

A. It operates on a specific object B. It is defined within a class C. It has access to the `this` keyword D. It cannot access fields of another object

28. Which keyword inside an instance method refers to the implicit parameter?

A. `self` B. `this` C. `super` D. `object`

29. Which of these is a correct example of an accessor method?

A. `public void setX(int newX) { x = newX; }` B. `public double distanceFromOrigin() { return Math.sqrt(x*x + y*y); }` C. `public void translate(int dx, int dy) { x += dx; y += dy; }` D. `public void reset() { x = 0; y = 0; }`

30. What does the following code do?

A. Sets x and y to dx and dy B. Translates point by dx and dy units C. Declares new variables dx and dy D. Resets x and y to zero

31. What is abstraction in the context of programming?

A. Providing full details of implementation to users B. Distancing between ideas and details C. Ignoring the state of objects D. Running programs procedurally

32. What is the function of the `new` keyword in Java?

A. Assign a value to a field B. Instantiate a new object C. Define a class D. Import packages

33. Which of the following best describes a mutator method?

A. It reads information about the object’s state B. It modifies the object’s internal state C. It creates new objects D. It terminates the object

34. If `p1` and `p2` are instances of class `Point`, which statement is true?

A. `p1.x` and `p2.x` refer to the same variable B. Each has its own copy of fields `x` and `y` C. They share a single `x` and `y` D. They do not have fields `x` and `y`

35. What does an object’s behavior refer to?

A. Its data fields B. Its methods C. Its class name D. Its memory location

36. How would you modify a field `y` in object `p2` to 13?

A. `p2.setY(13);` B. `p2.y = 13;` C. `p2.modify(y, 13);` D. `y.p2 = 13;`

37. Which of the following is a correct mutator method signature for `translate`?

A. `double translate(int dx, int dy)` B. `public void translate(int dx, int dy)` C. `void translate(double dx, int dy)` D. `private int translate(int dx, int dy)`

38. In Java, what is a class defined as?

A. A complete executable program B. A blueprint for a new data type C. A type of variable D. A subclass of an object

39. What syntax is used to call an instance method named `translate` on object `p1` with parameters `11` and `6`?

A. `translate(p1, 11, 6);` B. `p1.translate(11, 6);` C. `translate.11.6(p1);` D. `p1(translate, 11, 6);`

40. How does an object-oriented program differ from a procedural program?

A. It performs behavior as a series of steps B. It performs behavior as interactions between objects C. It only uses static methods D. It avoids using variables

41. Which of the following is true about fields in objects?

A. Fields are shared among all objects of the class B. Each object has its own copy of each field C. Fields cannot be accessed by clients D. Fields must always be public

42. In the blueprint analogy, what represents the "state" of an iPod?

A. The hardware specifications only B. Current song, volume level, battery life C. The brand of the iPod D. The packaging

43. What benefit does grouping related variables into an object provide?

A. It increases redundancy B. It makes programs longer C. It creates a new data structure with related data D. It eliminates the need for methods

44. Which term describes a variable inside an object that holds part of its state?

A. Method B. Field C. Parameter D. Class

45. What does a Java class primarily serve as in object-oriented programming?

A. A complete executable program B. A blueprint for creating objects C. A function to process data D. A database for storing variables

46. How can a mutator method give clients access to code?

A. Only read access B. Both read and write access C. No access D. Only write access

47. Which of the following best defines an accessor method?

A. A method that modifies an object's internal state B. A method that provides information without changing the state C. A method that deletes an object D. A method that creates an object

48. What is a field in an object?

A. A variable inside an object that is part of its state B. A method that modifies behavior C. An argument passed to a method D. The main method in a program

49. How do you access a field named `x` from an object named `p1`?

A. `p1.x` B. `x.p1` C. `p1[x]` D. `x:p1`

50. What is the output of calling `distanceFromOrigin()` if `x = 3` and `y = 4`?

A. 5.0 B. 7.0 C. 12.0 D. 1.0