Assume a class named yen exists. Write the header for a member function that overloads the \( < \) operator for that class.

C++ is a versatile and powerful programming language that enables developers to create complex software systems. One of the features that set C++ apart is its support for object-oriented programming (OOP). OOP allows developers to create objects that encapsulate data and functionality, making it easier to manage complex systems by breaking them down into manageable chunks.

In the context of the exercise given, C++ programming involves not only understanding the syntax of the language but also grasping concepts like classes and object-oriented design. The exercise requires one to define a class and then implement an operator overloading function within it. This approach to problem-solving is typical in C++, where operators can be customized to work with user-defined types, thus extending the language's functionality and making it possible to work with objects as intuitively as with basic data types.

Class member functions are the operations that objects of a C++ class can perform. Think of them as the actions or abilities of the class. Each member function can access the data members (variables) of the same class and manipulate them as needed.

In our exercise, the 'operator<' must be a member function since it needs to compare two 'yen' objects. By making it a member function, you ensure that it has direct access to the private data of the 'yen' class. This direct access is crucial for the function to perform its comparison task. Furthermore, marking the function as 'const' after the parameter list indicates that the function does not modify the object on which it's called, which is a good practice when writing functions that are not supposed to change the state of the object.

Operators in C++ are symbols that tell the compiler to perform specific mathematical or logical manipulations. C++ provides a set of built-in operators, such as '+' for addition or '==' for equality comparison, but one of its noteworthy features is the ability to overload these operators for user-defined types.

Operator overloading allows objects of custom types to be used with these operators. In the provided exercise, the '<' (less than) operator is being overloaded. This means that when two 'yen' objects are compared using '<', the compiler knows to use the custom-defined comparison logic encapsulated within the operator overload function. The operator overloading function takes another 'yen' object as a parameter and, typically, returns a boolean indicating the result of the comparison. This way, C++ enables a more intuitive interaction with objects by using natural operator syntax.