Definition

C++

What is C++?

C++ is an object-oriented programming (OOP) language that is viewed by many as the best language for creating large-scale applications. C++ is a superset of the C language.

A related programming language, Java, is based on C++ but optimized for the distribution of program objects in a network such as the internet. Java is somewhat simpler and easier to learn than C++ and has characteristics that give it other advantages over C++. However, both languages require a considerable amount of study.

C++ allows software developers to define their own data types and manipulate them using functions and methods. It also allows low-level programming and provides access to memory, enabling fast and efficient execution of code. It also supports generic programming using templates, which let code be written in a generic form and reused for different data types.

C++ is used in fields such as system software, game development, embedded systems, scientific computing and high-performance applications. The C++ standard library provides a range of coding utilities and functions, making it easy to develop complex software systems. C++ can run on many platforms, including Linux, Mac and Windows.

Diagram showing the four key elements of object-oriented programming
Object-oriented programming is a type of programming language that uses classes, properties, objects and methods.

How to use C++

There are several ways to learn C++, such as online tutorials, courses and interactive exercises. To start programming in C++, developers need a C++ compiler that translates code into machine-readable instructions. C++ compilers include Clang, GNU Compiler Collection and Microsoft Visual C++. Once a compiler is installed, developers can use a text editor or integrated development environment (IDE) to write C++ code. IDEs offer features such as code completion, debugging tools and management capabilities.

C++ programs are usually organized into functions. The main() function is the entry point of the computer program where execution begins. Developers can use control structures such as loops and conditionals to control their program's flow. C++ also provides a set of libraries that offer prebuilt functions and data structures for common tasks.

List of steps followed by code compilers
C++ uses compilers, which perform several analytical steps before outputting code.

How to write C++ code

When writing code in C++, the following are some basic functions:

C++ code. One of the easiest codes for beginners is the "Hello World!" code which uses the iostream library and the std namespace:

#include <iostream>

Int main(){

std::cout<<"Hello, World! <<std:endl;

return 0

}

In this example, the line #include <iostream> enables input/output functionality. Additionally, using std::cout lets the output be printed to the console. The std::endl line provides a line break. The return 0 statement indicates a successful program execution.

Arrays and memory allocation. C++ allows developers to work with arrays, which are collections of elements of the same data type. Here's an example of initializing and accessing elements in an array:

#include <iostream>



int main() {

int numbers[5] = {1, 2, 3, 4, 5};



for (int i = 0; i < 5; i++) {

std::cout << numbers[i] << " ";

}



return 0;

}

In this instance, developers declare an array numbers of size 5 and initialize its elements using curly braces {}. The for loop allows users to iterate over the array and print each element using std::cout.

C++ classes and constructors. C++ supports OOP with the use of classes. Here's an example of a simple class with a constructor and member functions:

#include <iostream>



class Rectangle {

private:

int length;

int width;



public:

Rectangle(int l, int w) {

length = l;

width = w;

}



int calculateArea() {

return length * width;

}

};



int main() {

Rectangle myRectangle(5, 3);

int area = myRectangle.calculateArea();

std::cout << "Area: " << area << std::endl;



return 0;

}

Developers can define a class called Rectangle with private data members length and width. The constructor Rectangle(int l, int w) initializes the object's attributes, while the member function calculateArea () calculates and returns the area of the rectangle.

Polymorphism and C++ standard library. C++ supports polymorphism, allowing objects to be treated as instances of their base or derived classes interchangeably. Additionally, the C++ standard library provides a rich set of functionalities. The following is an example:

#include <iostream>



class Shape {

public:

virtual void display() {

std::cout << "Shape" << std::endl;

}

};



class Circle : public Shape {

public:

void display() {

std::cout << "Circle" << std::endl;

}

};



int main() {

Shape* shape = new Circle();

shape->display(); // Polymorphism



delete shape; // Memory deallocation



return 0;

}

A base class Shape and a derived class Circle are defined. The display () function is marked as virtual in the base class, enabling polymorphism. By creating a Circle object and assigning it to a Shape pointer, a developer can invoke the derived class's display() function.

What are the uses of C++?

C++ is used in a wide range of ways to capitalize on its versatility and performance. Some of the main uses of C++ include the following:

  • Operating systems (OSes). C++'s low-level capabilities allow for efficient memory management and system resource controls, making it well-suited for the development of OSes.
  • Games and graphics. C++'s high performance and ability to interact with hardware makes it a good choice for game engines such as Epic Games' Unreal Engine and Unity Technologies' Unity, which are built using C++. The programming language is also used for graphics programming tasks, such as real-time rendering, image processing and physics simulations.
  • Embedded systems. C++ is commonly used in the development of embedded systems, which are computer systems designed to perform specific tasks. Examples of embedded systems include medical devices, automotive systems and internet of things devices.
  • Software libraries. C++ serves as the foundation for many high-level libraries used in various domains. Libraries like Boost provide additional functionality and utilities for C++ programmers, while the Standard Template Library (STL) offers a collection of generic data structures and algorithms. These libraries provide ready-to-use components, enhancing developer productivity.
  • High-performance computing (HPC). C++ is well suited for HPC applications that require maximum computational efficiency and parallel processing. It's used in scientific simulations, numerical analysis, mathematical modeling and simulations of physical phenomena. It's often used alongside specialized libraries such as message passing interface and OpenMP for distributed and parallel computing.
  • Web development. Although C++ isn't commonly used for web development, it plays a crucial role in the back end of web applications, such as web servers, network protocols, routers and communication software. Many web frameworks and servers, including the Apache HTTP Server, are implemented in C++. The language's speed and reliability make it suitable for handling high-traffic websites and complex server-side operations.
  • Systems programming. C++ is often used for systems programming tasks, where interaction with the underlying hardware and OS is required. Tasks such as device drivers, network protocols and system utilities are typically implemented in C++.

Advantages and disadvantages of C++

C++ comes with a mix of advantages and disadvantages. Some of its advantages such as high-performance and control come with the challenge of complexity and steep learning curves.

Advantages of C++

C++ benefits meet developers' many demands of programming languages:

  • High performance from C++'s low-level memory manipulation and direct access to hardware, making it suitable for resource-intensive applications.
  • Control, such as low-level control over system resources, which enables developers to fine-tune their programs for optimal performance.
  • Flexibility resulting from functionality such as the support of OOP and procedural and functional programming, the latter of which is increasingly embraced at enterprise scale.
  • Software portability that lets programs run on several different platforms.
  • Compatibility coming from C++'s interoperability with other programming languages such as C and its support across different platforms. This lets developers reuse code and use third-party libraries.
  • An expansive ecosystem tied to C++'s ability to use a large array of libraries and frameworks that offer prebuilt approaches for tasks, such as data manipulation, which reduces the need for manual implementation.

Disadvantages of C++

C++ also comes with some disadvantages, including the following:

  • Complexity and a challenging learning curve for beginners because of its extensive feature set.
  • Manual memory management, which can lead to memory leaks and other memory management issues if not handled properly.
  • Security risks related to C++'s direct access to memory, which increases risk of writing unsafe code.
  • Lack of built-in garbage collection, forcing developers to manually deallocate memory when it's no longer needed.
  • Complex syntax compared to other programming languages, making code reading and writing more time-consuming.
  • Long compile time compared to languages with dynamic typing or just-in-time compilation.

Examples of C++ tools

There are several tools and frameworks for C++ development that can enhance productivity, aid in-code organization and facilitate debugging and testing. Some of those tools include the following:

  • Integrated development environments. IDEs assist programmers in writing, debugging and managing code. IDEs used for C++ programming include Microsoft Visual Studio, which provides debugging and project management tools; JetBrains CLion, a cross-platform IDE that has refactoring tools; and Eclipse CDT, an open source IDE with code navigation and project management tools.
  • Build systems. Build systems help simplify the C++ build process by simplifying platform-specific build scripts and specifying dependencies and commands. Examples of these are CMake and GNU Make, both open source applications.
  • Testing frameworks. Testing frameworks let developers write and test code functionality. Google Test is an example of a testing framework that offers a set of assertion macros and utilities. Catch2 is a lightweight framework that provides a syntax for defining test cases, assertions and test fixtures. Boost.Test is a component of the Boost C++ Libraries that supports various testing styles and assertions.
  • Profiling tools. Profiling tools help developers analyze code performance using data on bottlenecks, resource use and execution. Valgrind is an open source profiling tool for performance analysis, memory profiling and leak detection. Intel VTune Amplifier is a tool that helps identify bottlenecks.
  • Documentation tools. Documentation tools are software utilities that automate the generation of source code documentation. Doxygen is one such tool that uses source code comments to document in Hypertext Markup Language, PDF and other formats.
  • Package managers. Package managers help manage a project's dependencies and libraries through a centralized interface. They help developers discover, install, update and remove software packages. Some package managers on the market include JFrog's Conan, a decentralized C/C++ package manager that simplifies dependency management and facilitates the integration of third-party libraries; and vcpkg, a cross-platform manager developed by Microsoft that offers a range of precompiled C++ libraries.

C++ vs. Java and Python

C++ is often compared with Java, Python and other programming languages. Each language has distinct characteristics that make them suitable for different purposes and paradigms.

Java

Java differs from C++ in the following ways:

  • Its syntax is similar to C++ and supports conditionals, loops and function definitions; however, it's designed to be simpler and more beginner-friendly.
  • Java uses an automatic garbage collector, but it doesn't use the const keyword, commonly used in C++.
  • Java emphasizes OOP more than C++, using classes and objects as its foundation and providing built-in support for virtual functions.
  • Java's standard library provides a range of classes and APIs for networking, database connectivity, GUI development and working with iterators.
List of Java features
Java is similar to C++ in its syntax and flexibility, though it contains other unique features as well.

Python

Python is distinct from C++ in the following ways:

  • Python's design emphasizes code clarity and expressiveness, and it uses fewer symbols and keywords.
  • Python is dynamically typed unlike C++ and Java, as a result, variable types are inferred at runtime. This simplifies development but potentially at the cost of performance.
  • Python uses an automatic garbage collector like Java and doesn't use the C++ const keyword.
  • Python is an interpreted language, so it doesn't require compilation before execution like C++.
  • Python's standard library includes support for literals and default arguments, and its third-party libraries include modules for domains, such as scientific computing and data analysis.
  • Web developers often use Python; it provides modules for working with semantics and specifiers similar to JavaScript and PHP.
Table comparing DevOps languages
C++ is often compared to Python and other DevOps programming languages; it stands out with its fast execution speed.

History of C++

Danish computer scientist Bjarne Stroustrup developed C++ in 1983 as an extension of the C programming language. Stroustrup initially used the language Simula, an OOP language, to extend C with the goal of combining object-orientation's encapsulation, inheritance and polymorphism features with the low-level capabilities of C.

C++ has gone through multiple iterations and standardization efforts. The first international standard for C++ was published in 1998 as ISO/IEC 14882:1998. Subsequent iterations of C++ have introduced new language features, improved performance and expanded the capabilities of the language.

C++ is a superset of the C programming language. Learn about the 11 cloud programming languages developers need to know.

Editor's note: The publisher has used ChatGPT in the creation of the code portion of this definition. The final code has been reviewed and approved by TechTarget editors.

This was last updated in August 2023

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