Question

Consider the following declaration: template class strange { . . . private: type a; type b; }; a. Write a statement that declares sObj to be an object of type strange such that the private member variables a and b are of type int. b. Write a statement that shows the declaration in the class strange to overload the operator == as a member function. c. Assume that two objects of type strange are equal if their corresponding member variables are equal. Write the definition of the function operator== for the class strange, which is overloaded as a member function.

Short answer

a) `strange sObj;` b) `bool operator==(const strange& other) const;` c) `return (a == other.a && b == other.b);`

Step-by-step solution

Declare sObj with int type

To declare an object \( sObj \) of type \( strange \) with private member variables \( a \) and \( b \) of type \( int \), you use the following statement: ```cpptemplate class strange;strange sObj;```

Overload operator== Declaration

In the class \( strange \), declare the operator == function to overload it. Place this declaration under the public access modifier: ```cpppublic: bool operator==(const strange& other) const;```

Define operator== Function

The function \( operator== \) is defined to compare the member variables of the object. The function returns true if both objects' member variables are equal: ```cpptemplate bool strange::operator==(const strange& other) const { return (a == other.a && b == other.b);}```

Key concepts

Operator Overloading in C++

In C++, operator overloading allows developers to redefine the functionality of built-in operators for user-defined types. This means you can customize how operators behave when used with objects of a class. For example, you might want to compare two objects of a class using the `==` operator. Through operator overloading, this can be achieved by defining a specific function for that operator.

Here's a quick rundown of the essentials for overloading an operator in C++:

• The overloaded operator must be declared within a class.
• You can make it a member function or a friend function.This depends on how access to private members is managed.
• Most operators can be overloaded, but there are exceptions, such as `::`, `?:`, and `.`.
• The overloaded operator must have at least one operand that is of a user-defined type.

In context, to overload the `==` operator within the class `strange`, you declare it as a class member function. This function will accept another object of the same class and return a `bool` indicating whether member variables of this object and the passed object are equal. The defined function for this exercise checks if both member variables of the objects (`a` and `b`) are equal. If they are, the function returns `true`; otherwise, it returns `false`.

Class Member Functions

Class member functions perform operations on the data members of a class in C++. These functions are integral components of OOP, encapsulating behavior and functionality related to the object itself. Whilst some class member functions manage internal state, others access or process data without altering it.

They contribute significantly to:

• Encapsulation, by controlling how an object's data is accessed and modified.
• Abstraction, by providing a clear interface through which the object can be interacted with.
• Reusability, enabling repetitive tasks to be succinctly defined within a class for reuse.

In the `strange` class example, declaring `operator==` as a member function allows it to directly compare the member variables `a` and `b` with those of another `strange` object. It demonstrates how member functions can leverage access to private data members to perform operations essential to the class's purpose. Once declared under the `public` access specifier, these functions can be readily accessed by other objects or functions that interact with the instance.

Template Programming in C++

Template programming in C++ is a feature that allows functions and classes to operate with generic types. This means a class or function can handle data of any type without being rewritten for each one. Templates provide powerful tools for creating flexible and reusable code.

Key aspects of template programming include:

• Generic programming, where you use a single definition to handle multiple data types.
• Compile-time polymorphism, which allows functions and classes to be determined at compile time rather than runtime.
• Type safety, as the compiler ensures that only valid operations are performed on data.

In our `strange` class example, the template class is declared with `template `. This specifies that `type` can be substituted with any data type when an object of the template class is created. For instance, `strange` creates an object where `a` and `b` are of type `int`. Template programming thus makes your code adaptable to change, which is crucial in scenarios requiring high maintainability and scalability.