All Flashcards
What does the following code output? Student s = new Student(9, "Jane Doe", 14); s.setGradeLevel(10); System.out.println(s.getGradeLevel());
10
Identify the error in the following code: public class Example { private int value; public void setValue() { value = 10; } }
The setValue method requires a parameter to set the value. It should be public void setValue(int newValue).
What does the following code output? Student s = new Student(9, "Jane Doe", 14); s.setName("Jane Smith"); System.out.println(s.getName());
Jane Smith
Complete the following code snippet to create a mutator method for the 'age' instance variable in the Student class: public class Student { private int age; // Complete the mutator method here }
public void setAge(int newAge) { age = newAge; }
What does the following code output? Student s = new Student(10, "Alice", 15); s.setGradeLevel(11); Student t = s; t.setGradeLevel(12); System.out.println(s.getGradeLevel());
12
Identify the error in the following code: public class Student { private String name; public String setName(String newName) { name = newName; } }
The return type of the setName method should be void, not String.
What does the following code output? Student s = new Student(9, "Jane Doe", 14); s.setName(null); System.out.println(s.getName());
null
Complete the following code snippet to add a validation check in the setGradeLevel mutator method: public class Student { private int gradeLevel; public void setGradeLevel(int newGradeLevel) { // Add validation check here } }
if (newGradeLevel >= 9 && newGradeLevel <= 12) { gradeLevel = newGradeLevel; }
What does the following code output? Student s = new Student(10, "Alice", 15); s.setGradeLevel(11); System.out.println(s.toString());
The output will vary depending on the implementation of the toString method in the Student class, but it will include the updated gradeLevel (11) and the student's other attributes.
Identify the potential issue in the following code: public class Student { private String name; public void setName(String newName) { name = newName.trim(); } }
If newName is null, newName.trim() will throw a NullPointerException. A null check should be added before calling trim().
How are mutator methods applied in a banking application?
Used to update account balances, such as deposit and withdrawal operations.
How are mutator methods applied in a game development context?
Used to change the position, health, or score of game characters or objects.
How are mutator methods applied in a social media application?
Used to update user profiles, such as changing names, profile pictures, or privacy settings.
How are mutator methods applied in an e-commerce application?
Used to update product inventory, change prices, or process orders.
How are mutator methods applied in a content management system (CMS)?
Used to update articles, blog posts, or other content items.
How are mutator methods applied in a database management system (DBMS)?
Used to update records in tables, such as changing customer information or product details.
How are mutator methods applied in a graphical user interface (GUI) framework?
Used to update the properties of GUI elements, such as changing the text of a label or the color of a button.
How are mutator methods applied in a network communication protocol?
Used to update the state of network connections, such as changing the connection status or the amount of data being transmitted.
How are mutator methods applied in a machine learning algorithm?
Used to update the weights or parameters of the model during training.
How are mutator methods applied in an operating system?
Used to update system settings, such as changing the screen resolution or the keyboard layout.
What are the differences between accessor and mutator methods?
Accessor: Retrieves the value of an instance variable. | Mutator: Modifies the value of an instance variable.
Compare a class with only accessor methods vs. a class with only mutator methods.
Accessor-only: Exposes data, read-only. | Mutator-only: Allows modification, no direct data access.
What are the differences between using direct access to instance variables and using mutator methods?
Direct access: Simple, but violates encapsulation. | Mutator methods: Encapsulated, allows validation, more controlled.
Compare the use of void vs. non-void mutator methods.
Void: No return value, modifies only. | Non-void: Can return previous value or status, allows chaining.
What are the differences between immutable and mutable objects?
Immutable: Cannot be changed after creation. | Mutable: Can be changed after creation via mutator methods.
Compare the use of mutator methods with and without validation.
Without validation: Faster, but can lead to invalid state. | With validation: Slower, but ensures data integrity.
What are the differences between public and private mutator methods?
Public: Accessible from anywhere. | Private: Only accessible within the class, used for internal state management.
Compare the use of mutator methods in single-threaded vs. multithreaded environments.
Single-threaded: Simpler, no need for synchronization. | Multithreaded: Requires synchronization to prevent race conditions.
What are the differences between using mutator methods and using reflection to modify object state?
Mutator methods: Safe, controlled access. | Reflection: Powerful, but can bypass encapsulation and lead to unexpected behavior.
Compare the use of mutator methods in procedural vs. object-oriented programming.
Procedural: Less common, data and functions are separate. | Object-oriented: Integral part of encapsulation and object state management.