What is constructor function?

A constructor is a special type of member function of a class which initializes objects of a class . In C++, Constructor is automatically called when object(instance of class) is created. It is special member function of the class because it does not have any return type.

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Why do we need no-arg constructor?

The arguments of a constructor can only be found by type, not by name, so there is no way for the framework to reliably match properties to constructor args . Therefore, they require a no-arg constructor to create the object, then can use the setter methods to initialise the data.

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