(a) What is class in C++? Elaborate in details. (b) Create a class Calculator which contains only a single component of type double. The class implements the four arithmetic operations: addition, subtraction, multiplication and division. The class can be used, by example, in this way: Calculator a(20), b(30), c, d, e, f, c = a + b; d = a - b; e = a'b; f = b/%3; cout The structure of the class looks like : class Calculator { private: double a; public: II The constructor II Overloaded the + operator II Overloaded the - operator I/ Overloaded the operator II Overloaded the / operator H Overloaded the input >> operator 1 Overloaded the output < < operator Implement or overload the methods of the class: a. the constructor b. the + operator c. the - operator d. the * operator e. the / operator f. the input >> operator g. the output < < operator (20 Marks) and write a test program to test the class methods.