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Please write a thorough response to explain each question about Classes and Dbjects in Java. Please see the rubric for what constitutes "thorough".

1. What is encapsulation and why is it useful?
2. What is an instance method and how does it differ from the static methods we learned previously?
3. What is a mutator method? What is an accessor method?
4. What is a constructor in a Java class?
5. What is an implicit parameter?

1 Answer

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Final answer:

Encapsulation in Java combines data with methods to protect it, instance methods operate on object instances unlike static methods, mutator and accessor methods allow object state modification and state access respectively, a constructor initializes objects, and an implicit parameter is the object upon which methods are called.

Step-by-step explanation:

Firstly, encapsulation is a principle of bundling the data (variables) and the methods (functions) that operate on the data into a single unit, known as a class in Java. It is useful because it helps in protecting the data from outside interference and misuse, such as by restricting access to the data through access modifiers (public, private, etc.).

An instance method operates on an object and has access to its instance variables, whereas a static method belongs to the class itself and does not require an object to be invoked. Static methods can only operate on static data and can be called using the class name directly.

A mutator method is used to set or modify the value of an object's state, while an accessor method is used to read the data of an object. These methods are also known as setters and getters respectively.

A constructor in a Java class is a special type of method that is used to initialize the objects of the class. It is called when an object of the class is created and can be used to set initial values for the object's attributes.

Finally, an implicit parameter refers to the object on which an instance method is called. Inside the method, the implicit parameter can be referred to with the keyword 'this' to access the object's instance variables and other methods.

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