Can we make constructor as 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 happens if I make a constructor private?

A private constructor in Java is used in restricting object creation. It is a special instance constructor used in static member-only classes. If a constructor is declared as private, then its objects are only accessible from within the declared class. You cannot access its objects from outside the constructor class.

Can constructor be private or protected?

Modifiers public, protected and, private are allowed with constructors. We can use a private constructor in a Java while creating a singleton class.

Are there private constructors?

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.

Is constructor private or public?

No, Constructors can be public , private , protected or default (no access modifier at all). Making something private doesn't mean nobody can access it. It just means that nobody outside the class can access it. So private constructor is useful too.

Can a Constructor be private in Java ?

Can we declare constructor as static?

Java constructor can not be static

One of the important property of java constructor is that it can not be static. We know static keyword belongs to a class rather than the object of a class. A constructor is called when an object of a class is created, so no use of the static constructor.

Can we declare constructor as final?

No, a constructor can't be made final. A final method cannot be overridden by any subclasses. As mentioned previously, the final modifier prevents a method from being modified in a subclass. The main intention of making a method final would be that the content of the method should not be changed by any outsider.

Can a constructor be virtual?

Virtual Constructor in C++

In C++, the constructor cannot be virtual, because when a constructor of a class is executed there is no virtual table in the memory, means no virtual pointer defined yet. So, the constructor should always be non-virtual. But virtual destructor is possible.

How do you make a constructor object private?

We can declare a constructor private by using the private access specifier. Note that if a constructor is declared private, we are not able to create an object of the class. Instead, we can use this private constructor in Singleton Design Pattern.

Can constructor be overridden?

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.

Can constructor be overloaded?

Constructors can be overloaded in a similar way as function overloading. Overloaded constructors have the same name (name of the class) but the different number of arguments. Depending upon the number and type of arguments passed, the corresponding constructor is called.

Why constructor is private in Singleton?

In singleton class, we use private constructor so that any target class could not instantiate our class directly by calling constructor, however, the object of our singleton class is provided to the target class by calling a static method in which the logic to provide only one object of singleton class is written/ ...

Can a constructor be private in C++?

Typically, constructors have public accessibility so that code outside the class definition or inheritance hierarchy can create objects of the class. But you can also declare a constructor as protected or private .

Can abstract method be private?

Abstract classes can have private methods. Interfaces can't. Abstract classes can have instance variables (these are inherited by child classes). Interfaces can't.

Can we declare private constructor in class?

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.

Can we make destructor as private?

Private Destructor in C++ Destructors with the access modifier as private are known as Private Destructors. Whenever we want to prevent the destruction of an object, we can make the destructor private.

Can we create pointer of abstract class?

You can't create an object of an abstract class type. However, you can use pointers and references to abstract class types. You create an abstract class by declaring at least one pure virtual member function. That's a virtual function declared by using the pure specifier ( = 0 ) syntax.

Can we use abstract keyword with constructor?

Since you cannot override a constructor you cannot provide body to it if it is made abstract. Therefore, you cannot use abstract keyword with the constructor.

Can we override static method?

Overloading is the mechanism of binding the method call with the method body dynamically based on the parameters passed to the method call. Static methods are bonded at compile time using static binding. Therefore, we cannot override static methods in Java.

Can we create immutable class in Java?

Immutable class in java means that once an object is created, we cannot change its content. In Java, all the wrapper classes (like Integer, Boolean, Byte, Short) and String class is immutable. We can create our own immutable class as well.

Can a main () method be declared final?

Yes, we can declare the main () method as final in Java. The compiler does not throw any error. If we declare any method as final by placing the final keyword then that method becomes the final method.

Can constructor be void?

Note that the constructor name must match the class name, and it cannot have a return type (like void ). Also note that the constructor is called when the object is created.

Can you declare an abstract class as final?

If you declare a class abstract, to use it, you must extend it and if you declare a class final you cannot extend it, since both contradict with each other you cannot declare a class both abstract and final if you do so a compile time error will be generated.

Can we declare interface as final?

If you make an interface final, you cannot implement its methods which defies the very purpose of the interfaces. Therefore, you cannot make an interface final in Java. Still if you try to do so, a compile time exception is generated saying “illegal combination of modifiers − interface and final”.

Can static methods be private?

Yes, we can have private methods or private static methods in an interface in Java 9.