Can an immutable class be inherited?
Immutable objects cannot change after they are created. If the immutable class can be inherited, the subclass can change the methods to modify the instances of the class, so an immutable class cannot allow this. In summary, an immutable object: Sets all of its properties through a constructor.
What is an immutable class how do you create an immutable class?
To create an immutable class in Java, you have to do the following steps.
- Declare the class as final so it can’t be extended.
- Make all fields private so that direct access is not allowed.
- Don’t provide setter methods for variables.
- Make all mutable fields final so that its value can be assigned only once.
Can we create immutable class without final keyword?
The final keyword won’t make your class inmutable. It will avoid your class to be extended from another class.
How to make a class immutable in Java?
Don’t provide methods that modify the object’s state: These are the setter methods in a class that set the values of the instance variables. Ensure that the class cannot be extended: This is done so that a subclass does not modify the state of the object. This is typically done by making the class final.
Which is the only mutable component in a Java class?
Defensive copying refers to the approach of returning a copy or a clone of a mutable data structure thereby not exposing the mutable object. In our class, the only mutable component or field is the map that holds the item to quantity.
How to ensure exclusive access to any mutable component?
Ensure exclusive access to any mutable components: If the class has any mutable instance variables, make defensive copies in the constructor and in the accessors (getters). We should not initialize such fields to a client-provided reference. The below class represents a shopping cart.