All Flashcards
What is a mutator method?
A method that changes the values of instance variables of an object.
What is another name for mutator methods?
Setter methods.
What does 'void' mean in the context of a method?
The method does not return any value.
What is an immutable class?
A class with no mutator methods, meaning its state cannot be changed after creation.
What is the typical return type of a mutator method?
void
What is the purpose of a parameter in a mutator method?
To provide the new value to which the instance variable will be set.
What is an instance variable?
A variable defined in a class for which every object of the class has its own copy.
What is the difference between accessor and mutator methods?
Accessor methods retrieve the values of instance variables, while mutator methods modify them.
Why might a class not have a mutator method for a specific instance variable?
To prevent clients from changing the data of that instance variable, ensuring data integrity.
What is the signature of a mutator method?
Typically 'public void methodName(DataType parameterName)'
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.