Question: What Happens If There Is No Constructor?

Can a class have multiple constructors?

There can be multiple constructors in a class.

However, the parameter list of the constructors should not be same.

This is known as constructor overloading..

Does constructor have any return type?

No, constructor does not have any return type in Java. … It does not have a return type and its name is same as the class name. Mostly it is used to instantiate the instance variables of a class. If the programmer doesn’t write a constructor the compiler writes a constructors on his behalf.

Can a constructor return a value C++?

Constructors are functions that do not return a value. The family of functions that do not return a value consists of: void functions, constructors and destructors. It is stated in 6.6. 3/2 in the C++ standard.

Can a class run without constructor?

It is possible for a class to have no constructor. (An important distinction to draw here is that the JVM does not require all class files to have a constructor; however, any class defined in Java does have a default constructor if a constructor is not explicitly declared.

Can a constructor be empty?

An empty constructor is needed to create a new instance via reflection by your persistence framework. If you don’t provide any additional constructors with arguments for the class, you don’t need to provide an empty constructor because you get one per default.

Can we inherit a constructor?

Constructors are not members, so they are not inherited by subclasses, but the constructor of the superclass can be invoked from the subclass.

Which operators Cannot be overloaded and why?

Operators that cannot be overloaded in C++ For an example the sizeof operator returns the size of the object or datatype as an operand. This is evaluated by the compiler. It cannot be evaluated during runtime. So we cannot overload it.

How many constructors can a class have?

You can have 65535 constructors in a class(According to Oracle docs).

Why constructor have no return type?

So the reason the constructor doesn’t return a value is because it’s not called directly by your code, it’s called by the memory allocation and object initialization code in the runtime. … The whole purpose of constructor is to initialize the current state of the object by setting the initial values.

Can we declare constructor as static?

No, we cannot define a static constructor in Java, If we are trying to define a constructor with the static keyword a compile-time error will occur. In general, static means class level. A constructor will be used to assign initial values for the instance variables.

Can a constructor return a value?

No, constructor does not return any value. While declaring a constructor you will not have anything like return type. In general, Constructor is implicitly called at the time of instantiation.

Can a class have two different no args constructors?

Yes. A private contructor is a special instance constructor. It is commonly used in classes that contain static members only. If a class has one or more private constructors and no public constructors, then other classes (except nested classes) are not allowed to create instances of this class.

Why constructor has no return type not void?

Constructor is internally a nonstatic method with name and void return type. It does not return anything. … Object is not allocated with constructor itself. In other words the syntax new Object() not only calls the constructor but also creates new object and after calling the constructor returns it.

Can constructors be overloaded?

Yes! Java supports constructor overloading. In constructor loading, we create multiple constructors with the same name but with different parameters types or with different no of parameters.

Can constructor be overloaded Examveda?

Explanation: The constructor must be having the same name as that of a class. Hence a constructor of one class can’t even be defined in another class. Since the constructors can’t be defined in derived class, it can’t be overloaded too, in derived class.

Can method be overloaded?

In Java, two or more methods can have same name if they differ in parameters (different number of parameters, different types of parameters, or both). These methods are called overloaded methods and this feature is called method overloading. For example: … These methods have the same name but accept different arguments.

What happens when a class has no constructor?

The compiler automatically provides a public no-argument constructor for any class without constructors. This is called the default constructor. If we do explicitly declare a constructor of any form, then this automatic insertion by the compiler won’t occur.

What Cannot be inherited in Java?

No, constructors cannot be inherited in Java. In inheritance sub class inherits the members of a super class except constructors. In other words, constructors cannot be inherited in Java therefore, there is no need to write final before constructors.