Java Enum constructors private? [duplicate] - java

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Private enum constructor
(8 answers)
Closed 6 years ago.
I believe enum constructors in Java are meant to be private but I've recently switched over to IntelliJ and it says that the private keyword is redundant when I add it to the constructor.
Picture:
http://puu.sh/nYbwp/1c37312777.png
Does Java just automatically make them private or something?

yes. Enum constructor is private by design.
And it is not the only example of access modifier's redundancy in Java - all interface methods are public and public modifier for them is not necessary too

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Can we declare private constructor in abstract class? When this situation occurs? [duplicate]

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Private constructor in abstract class
(7 answers)
Closed 4 years ago.
Need to know can we declare private construct in abstract class and how to access it in Java.
The fact that it's an abstract class doesn't make a difference. A private constructor can only be accessed from within the class in which it is defined.
For example, it could be accessed from other constructors of that same class, using this().

Concept of encapsulation [duplicate]

This question already has answers here:
Simple way to understand Encapsulation and Abstraction
(16 answers)
Java Encapsulation Concept not clear
(12 answers)
Closed 4 years ago.
Concept of encapsulation:If we can change the value of private variable indirectly(through setters and getters), then how is the private variable secured, how is it hidden?Could someone please explain in detail..
You're correct. If a field is exposed via getters and setters, it is not encapsulated. It's annoying how many people don't understand this so it's not surprising that you're confused.
Check out this answer. Essentially, using the keyword private we are able to prevent outside use of the fields in a class, for example. It hides the data in a class associated with that private keyword.

what is static method why use this in Display class in java [duplicate]

This question already has answers here:
When to use static methods
(24 answers)
In laymans terms, what does 'static' mean in Java? [duplicate]
(6 answers)
Closed 5 years ago.
i am always use static keyword but don't know clearly what is main purpose of static keyword. can any define , this is use in java Display method in oop
Static methods are those methods can be called without creating its object.
It can be invoked using its class name.
Eg. Math.sqrt(25);
Where Math is the class name, not an object and static methods can access only static properties of the class.

How to use a private method from the super class in the sub class in Java? [duplicate]

This question already has answers here:
How do I access private methods and private data members via reflection?
(6 answers)
Closed 5 years ago.
I was just wondering how I would use something to get or use a private method from the super class in the sub class in java. I know that is a handful, but basically I want to know if I create a private method in a parent or super class, then what would be the code to bring in that private method into the sub class.
All help is greatly appreciated from this question.
NOTE:
I know that this question is similar to the question:
How can a derived class invoke private method of base class?
On this site Stack Overflow
However, the question answer for the question seem complex and hard to read for a beginner as well as not being the correct answer to the exact way that I am asking this question.
I want to know if I create a private method in a parent or super
class, then what would be the code (in the form of an accessor or
mutator method) to bring in that private method into the subclass.
You can't. That's what private means. Make it protected instead.

Why is the System class declared as "final" in Java? [duplicate]

This question already has answers here:
Java -- private constructor vs final and more
(3 answers)
Closed 7 years ago.
As per my understanding, a class is declared as final to prevent it from being extended/inherited. So I see there can be security and probably some performance gains in this regard.
But is there a very specific design decision behind this? Say for eg: to realize some kind of design pattern? I did go around a similar thread here! but the answer was not really what I was looking for
Singleton Pattern:
-Private Constructor
-Only static methods
-No need to have more than one object of this class or an object at all
-No need to extend this fundamental class

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