Ans : I have asked this question for C# language.
Private Constructor : It is used to prevent class to be instantiated and to be inherited. Class can have multiple private constructor and can be called by any other constructor.
Static Constructor : It is used to initialise static members of a class. We can't say when it is called and It is called by CLR and not called by manually. It is called just before first instance of class is created. Class can have a only one static constructor. This constructor is called only once in lifetime of application.
Private Constructor : It is used to prevent class to be instantiated and to be inherited. Class can have multiple private constructor and can be called by any other constructor.
Static Constructor : It is used to initialise static members of a class. We can't say when it is called and It is called by CLR and not called by manually. It is called just before first instance of class is created. Class can have a only one static constructor. This constructor is called only once in lifetime of application.