Start Coding

Subjects

JAVASCRIPTHTMLCSSPYTHONSQLJAVACPPCSHARPPHPTYPESCRIPTCRUBYGOSWIFTKOTLINRUSTRBASHSCALAOBJECTIVE-CDARTPERLLUAMATLABXMLJSONMARKDOWNASSEMBLYLATEXYAMLSOLIDITYBLOCKCHAIN

Topics

C++ Basics

Introduction to C++C++ History and EvolutionC++ Environment SetupC++ First ProgramC++ SyntaxC++ CommentsC++ Data TypesC++ VariablesC++ ConstantsC++ KeywordsC++ OperatorsC++ Input/Output

C++ Control Structures

C++ If-Else StatementsC++ Switch StatementsC++ For LoopsC++ While LoopsC++ Do-While LoopsC++ Break and ContinueC++ Goto Statement

C++ Functions

C++ Function BasicsC++ Function ParametersC++ Function OverloadingC++ Inline FunctionsC++ RecursionC++ Default ArgumentsC++ Lambda Expressions

C++ Arrays and Strings

C++ ArraysC++ Multidimensional ArraysC++ C-style StringsC++ String ClassC++ String FunctionsC++ String Streams

C++ Pointers and References

C++ Pointers BasicsC++ Pointer ArithmeticC++ ReferencesC++ Pointers vs ReferencesC++ Dynamic Memory AllocationC++ Smart Pointers

C++ Object-Oriented Programming

C++ Classes and ObjectsC++ Constructors and DestructorsC++ Access SpecifiersC++ EncapsulationC++ InheritanceC++ PolymorphismC++ Virtual FunctionsC++ Abstract ClassesC++ Interfaces (Pure Virtual)C++ Friend Functions and Classes

C++ Templates

C++ Function TemplatesC++ Class TemplatesC++ Template SpecializationC++ Variadic Templates

C++ Exception Handling

C++ Try-Catch BlocksC++ Throwing ExceptionsC++ Custom ExceptionsC++ Exception Specifications

C++ File Handling

C++ File I/O StreamsC++ Reading from FilesC++ Writing to FilesC++ Binary File Operations

C++ Standard Template Library

C++ STL ContainersC++ STL AlgorithmsC++ STL IteratorsC++ STL Function Objects

C++ Advanced Topics

C++ NamespacesC++ Preprocessor DirectivesC++ Type CastingC++ MultithreadingC++ Regular ExpressionsC++ Move SemanticsC++ Rvalue References

C++ Memory Management

C++ Stack vs HeapC++ Memory LeaksC++ Garbage CollectionC++ Custom Allocators

C++ Best Practices

C++ Coding StandardsC++ Performance OptimizationC++ Debugging TechniquesC++ Unit Testing

C++ Interfaces (Pure Virtual Functions)

In C++, interfaces are implemented using pure virtual functions, providing a powerful mechanism for defining abstract contracts that derived classes must fulfill. This concept is fundamental to achieving polymorphism and creating flexible, extensible code structures.

What are Pure Virtual Functions?

Pure virtual functions are special virtual functions that have no implementation in the base class. They are declared by assigning 0 to the function declaration:

virtual returnType functionName(parameters) = 0;

A class containing at least one pure virtual function is called an abstract class. Such classes cannot be instantiated directly but serve as interfaces for derived classes.

Creating an Interface in C++

To create an interface in C++, define a class with only pure virtual functions:

class Shape {
public:
    virtual double area() = 0;
    virtual double perimeter() = 0;
    virtual ~Shape() {} // Virtual destructor
};

This Shape class acts as an interface, defining a contract for any class that inherits from it. Derived classes must implement all pure virtual functions to be instantiable.

Implementing an Interface

To implement an interface, create a derived class and provide implementations for all pure virtual functions:

class Circle : public Shape {
private:
    double radius;

public:
    Circle(double r) : radius(r) {}

    double area() override {
        return 3.14159 * radius * radius;
    }

    double perimeter() override {
        return 2 * 3.14159 * radius;
    }
};

Benefits of Using Interfaces

  • Achieve abstraction by separating interface from implementation
  • Enable polymorphism, allowing for flexible and extensible code
  • Enforce a contract for derived classes, ensuring consistent behavior
  • Facilitate easier maintenance and future modifications

Best Practices

  1. Always declare a virtual destructor in interface classes to ensure proper cleanup of derived objects.
  2. Use the override keyword when implementing interface functions in derived classes for better code clarity and compiler checks.
  3. Keep interfaces focused and cohesive, following the Single Responsibility Principle.
  4. Consider using abstract classes when you need to provide some default implementations along with pure virtual functions.

Conclusion

Interfaces, implemented through pure virtual functions in C++, provide a powerful tool for designing flexible and extensible software systems. By mastering this concept, you can create more modular, maintainable, and scalable code structures in your C++ projects.

Remember to explore related topics such as inheritance and virtual functions to gain a comprehensive understanding of object-oriented programming in C++.