Question: Should Constructors Be Private Or Public?

Can we override private methods?

No, we cannot override private or static methods in Java.

Private methods in Java are not visible to any other class which limits their scope to the class in which they are declared..

Is class private in Java?

Java doesn’t allow a top level class to be private. Only ‘public’ or ‘package’. … If a class has no modifier (the default, also known as package-private), it is visible only within its own package (packages are named groups of related classes — you will learn about them in a later lesson.)

Can we overload private and final methods?

private and final methods can be overloaded but they cannot be overridden. It means a class can have more than one private/final methods of same name but a child class cannot override the private/final methods of their base class. … Argument list should be different while doing method overloading.

Why we Cannot override static method?

Static methods cannot be overridden because they are not dispatched on the object instance at runtime. The compiler decides which method gets called. Static methods can be overloaded (meaning that you can have the same method name for several methods as long as they have different parameter types).

Should methods be private or public?

The rule is that a method should be made provided unless it is needed. One of the main reasons for this is that in a future release of an API etc., you can always make a private function public, but you can almost never make a previous public function private without breaking existing code.

Should I test private method?

The short answer is that you shouldn’t test private methods directly, but only their effects on the public methods that call them. Unit tests are clients of the object under test, much like the other classes in the code that are dependent on the object. … The test should only be accessing the class’ public interface.

When should a constructor be private?

Private constructors are used to prevent creating instances of a class when there are no instance fields or methods, such as the Math class, or when a method is called to obtain an instance of a class. If all the methods in the class are static, consider making the complete class static.

What is the point of private variables?

Making a variable private “protects” its value when the code runs. At this level, we are not concerned with protecting it from other programmers changing the code itself. The point of so-called “data hiding” is to keep internal data hidden from other classes which use the class.

What is the difference between private and protected?

The class members declared as private can be accessed only by the functions inside the class. … The class member declared as Protected are inaccessible outside the class but they can be accessed by any subclass(derived class) of that class.

Can a constructor override?

Constructor looks like method but it is not. It does not have a return type and its name is same as the class name. But, a constructor cannot be overridden. If you try to write a super class’s constructor in the sub class compiler treats it as a method and expects a return type and generates a compile time error.

Is constructor can be private?

Yes, we can declare a constructor as private. If we declare a constructor as private we are not able to create an object of a class. We can use this private constructor in the Singleton Design Pattern.

What is the use of private?

We can’t assign private to outer class and interface. The best use of private keyword is to create a fully encapsulated class in Java by making all the data members of that class private. If we make any class constructor private, we cannot create the instance of that class from outside the class.

Are private methods bad?

Private methods are not inherently bad, but they are a sign that you might be missing out on an opportunity to make a useful abstraction. If you have a private method that calls another private method, then there is almost certainly an area of responsibility that remains unidentified.

Why we use public private and protected?

A public member is accessible from anywhere outside the class but within a program. … A protected member variable or function is very similar to a private member but it provided one additional benefit that they can be accessed in child classes which are called derived classes.

Is constructor public or private in C++?

A constructor is a special member function of a class which initializes objects of a class. In C++, constructor is automatically called when object of a class is created. By default, constructors are defined in public section of class.