Answer: C++ Empty constructor necessity depends upon class design requirements. We know that C++ class constructor is called when we create an object of a class. If a class is not required to initialize its data member or does not contain data member, there is no need to write empty constructor explicitly.
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Does C++ require a default constructor?
Answer: C++ Empty constructor necessity depends upon class design requirements. We know that C++ class constructor is called when we create an object of a class. If a class is not required to initialize its data member or does not contain data member, there is no need to write empty constructor explicitly.
What happens if you don’t have a default 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 does default constructor mean in C++?
A default constructor is a constructor that either has no parameters, or if it has parameters, all the parameters have default values. If no user-defined constructor exists for a class A and one is needed, the compiler implicitly declares a default parameterless constructor A::A() .
Do all C++ classes have a default constructor?
For example, all members of class type, and their class-type members, must have a default constructor and destructors that are accessible. All data members of reference type and all const members must have a default member initializer.
Can a class have no constructor C++?
If your class has no constructors, C++ will automatically generate a public default constructor for you. This is sometimes called an implicit constructor (or implicitly generated constructor). The Date class has no constructors.
What happens if no default constructor C++?
If no user-defined constructor exists for a class A and one is needed, the compiler implicitly declares a default parameterless constructor A::A() . This constructor is an inline public member of its class.
Why do we need a default constructor in class implementation C++?
What is the significance of the default constructor? They are used to create objects, which do not have any having specific initial value. Is a default constructor automatically provided? If no constructors are explicitly declared in the class, a default constructor is provided automatically.
How do you set a default constructor?
Java compiler automatically creates a default constructor (Constructor with no arguments) in case no constructor is present in the java class….Default constructor in Java
- Create the Object.
- Call the super class constructor()
- Initialize all the instance variables of the class object.
What is the purpose of default constructor?
Q) What is the purpose of a default constructor? The default constructor is used to provide the default values to the object like 0, null, etc., depending on the type.
Should you always have a default constructor?
Yes, you need to have a default constructor. The program won’t compile otherwise.
How many default constructors can a class have C++?
A default constructor is a constructor that is called without any arguments. It is not possible to have more than one default constructor.
What is the purpose of default keyword in C++?
It’s a new C++11 feature. It means that you want to use the compiler-generated version of that function, so you don’t need to specify a body. You can also use = delete to specify that you don’t want the compiler to generate that function automatically.