Question: Can A Class Have No Constructor?

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..

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.

Does every class have a constructor?

Every class has a constructor whether it’s a normal class or a abstract class. Constructors are not methods and they don’t have any return type. Constructor name should match with class name . Constructor can use any access specifier, they can be declared as private also.

Does every class need a constructor C++?

A class doesn’t need a constructor. A default constructor is not needed if the object doesn’t need initialization.

Can a constructor have no parameters?

No-argument constructor: A constructor that has no parameter is known as default constructor. If we don’t define a constructor in a class, then compiler creates default constructor(with no arguments) for the class. … If we want to initialize fields of the class with your own values, then use a parameterized constructor.

Can we make copy constructor private?

Yes, a copy constructor can be made private. When we make a copy constructor private in a class, objects of that class become non-copyable.

How do you call a constructor?

Invoking a constructor from a method No, you cannot call a constructor from a method. The only place from which you can invoke constructors using “this()” or, “super()” is the first line of another constructor. If you try to invoke constructors explicitly elsewhere, a compile time error will be generated.

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.

What do you call a constructor that accepts no arguments?

In both Java and C#, a “default constructor” refers to a nullary constructor that is automatically generated by the compiler if no constructors have been defined for the class. … A programmer-defined constructor that takes no parameters is also called a default constructor in C#, but not in Java.

Can constructor 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.

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.

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.

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 we inherit a constructor?

A subclass inherits all the members (fields, methods, and nested classes) from its superclass. Constructors are not members, so they are not inherited by subclasses, but the constructor of the superclass can be invoked from the subclass.

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.