Topic 2.3: Working With Java Data Types - Know how to read or write to object fields Flashcards
Can dot notation be used to access nested fields within an object?
Yes, dot notation can be chained to access nested fields within an object.
Example:
If we have an object called myObject, which contains another object nestedObject, and nestedObject has a field called nestedField, we can access it using dot notation like this:
myObject.nestedObject.nestedField
What does
immutability
refer to in Java?
This refers to the state of an object that cannot be changed after it is created.
This helps achieve data encapsulation by controlling access to the internal state of a class and protecting the fields from unauthorized access or modification.
What is the purpose of
encapsulating fields
in object-oriented programming?
What is the purpose of dot notation when accessing object fields?
This allows you to retrieve the value of a field belonging to a particular object or assign a new value to that field.
How does encapsulation promote flexibility and maintainability?
Encapsulation allows modification of the internal implementation of a class without impacting other parts of the code that use the class, promoting flexibility and easier maintenance.
What is the purpose of
encapsulating fields
in object-oriented programming?
This helps achieve data encapsulation by controlling access to the internal state of a class and protecting the fields from unauthorized access or modification.
What is one benefit of encapsulation and access methods?
One benefit is data integrity, as encapsulation prevents external code from directly modifying fields in an inconsistent or invalid manner.
What does an
object reference
hold if it is not pointing to any object?
If this is not pointing to any object, it holds the special value null.
What are getters and setters?
Getters are methods that provide read-only access to the values of private fields, allowing other classes to retrieve field values.
Setters are methods that provide write access to the values of private fields, allowing controlled modification with validations or transformations.
Can multiple reference variables point to the same object, and what happens when changes are made through one reference?
Yes, multiple reference variables can point to the same object. Changes made to the object’s fields through one reference will be reflected when accessed through other references to the same object.
What are the benefits of using
immutable objects?
These provide benefits such as:
- simplicity,
- thread safety,
- and the ability to safely share objects across different parts of a program.
What is the impact of immutability on object fields?
The immutability of an object ensures that its fields’ values remain constant throughout the object’s lifetime,
contributing to the stability and predictability of the object’s behavior.
The fields of this are typically declared as final.
How are the fields of an
immutable object
typically declared?
Why is it important to properly initialize object references before using them?
Proper initialization of these ensures they are valid and prevents NullPointerExceptions when accessing fields.
Proper initialization of these ensures they are valid and prevents NullPointerExceptions when accessing fields.
Why is it important to properly initialize object references before using them?
