Mastering C++: A Comprehensive Quiz Based on 'Thinking in C++'

What triggers the compiler to generate a default constructor in C++?

1. When the class has virtual functions

2. When no constructor is defined

3. When the class has static member variables

4. When the class inherits from another

The correct answer is: When no constructor is defined

When no constructor is defined, the compiler will automatically generate a default constructor for the class. This is because in C++, if no constructor is explicitly defined, the compiler will create one by default. This default constructor will initialize each data member of the class. The other options are incorrect because A: The presence of virtual functions does not affect the generation of a default constructor. However, it may affect the behavior of the constructor if it is explicitly defined by the user. C: The presence of static member variables does not trigger the generation of a default constructor. However, if the static member variables are non-const and non-static, then a user-defined constructor must be provided. D: Inheritance from another class does not necessarily trigger the generation of a default constructor. It depends on whether the base class has a default constructor or not. If the base class has a default constructor, then it