Features of C++

Introduction

C++ is a powerful, versatile, and popular programming language amongst many programmers in the world. It has been used to create different applications since its creation in 1979 by Bjarne Stroustrup. It was designed as an extension of the C programming language with added features like object-oriented programming, exception handling, and templates. The language provides developers with a high level of control over system resources and memory, which makes it suitable for developing resource-constrained & performance-critical applications.

In this article, we will discuss some of the key features that make C++ a popular choice among programmers.

Object-Oriented Programming

C++ supports object-oriented programming (OOP), a programming paradigm that organizes code into reusable objects. In OOP, data and functions are bundled together into classes, which serve as blueprints for creating objects. Each object has its own set of properties (data members) and behaviors (member functions), allowing for modular and maintainable code.

Let’s look at a simple example of a class in C++

class Rectangle {
private:
    int width;
    int height;
public:
    void setDimensions(int w, int h) {
        width = w;
        height = h;
    }


    int getArea() {
        return width * height;
    }
};

In this example, the `Rectangle` class has private data members `width` & `height`, & public member functions `setDimensions()` & `getArea()`. Objects of the `Rectangle` class can be created & used like this:

Rectangle rect;
rect.setDimensions(5, 3);
int area = rect.getArea();

Machine Independent

One of C++'s advantages is its machine independence, which means that C++ programs can be written and compiled on one platform and then run on another without significant modifications. This is possible because C++ compilers generate machine code specific to the target platform, abstracting away the underlying hardware details.

When you write a C++ program, you typically use a text editor to create source files with a `.cpp` extension. These source files are then compiled using a C++ compiler, such as GNU C++ Compiler (g++) or Microsoft Visual C++ Compiler (MSVC). The compiler translates the human-readable C++ code into machine code that can be directly executed by the computer's processor.

For example, let's say you have a simple C++ program called `hello.cpp`:

#include <iostream>


int main() {
    std::cout << "Hello, world!" << std::endl;
    return 0;
}

You can also try this code with Online C++ Compiler

Run Code

You can compile this program on a Linux machine using the g++ compiler like this:

g++ -o hello hello.cpp

This command compiles the `hello.cpp` file & generates an executable file named `hello`. You can then run the program by executing the `hello` file:

./hello

The same source code can be compiled on a Windows machine using MSVC, & the resulting executable will be compatible with the Windows operating system.

Note: Machine independence allows developers to write C++ code that can be easily ported to different platforms, saving time & effort in the development process.

Simple

C++ is known for its simplicity and easy syntax, which makes it relatively easy to learn and understand compared to some other programming languages. It builds upon the foundation of the C programming language, which is known for its simplicity and efficiency.

Let’s look at some aspects that make C++ a simple and easy-to-use language:

1. Procedural programming: C++ supports procedural programming, where the program is divided into functions that perform specific tasks. This allows for a clear & logical flow of the program.

2. Simple syntax: C++ has a concise & intuitive syntax that is similar to the English language. For example, the `if` statement in C++ closely resembles its English counterpart:

if (condition) {
    // code to execute if the condition is true
}

3. Standard libraries: C++ provides a rich set of standard libraries that offer pre-defined functions and classes for common tasks, such as input/output operations, string manipulation, and mathematical calculations. These libraries simplify the development process by providing ready-to-use tools.

4. Minimal keywords: Compared to some other languages, C++ has a relatively small set of keywords, making it easier to remember and understand the core language constructs.

5. Gradual learning curve: C++ allows beginners to start with the basics of procedural programming and gradually move on to more advanced concepts like object-oriented programming, templates, and exception handling as they gain more experience.

High-Level Language

C++ is considered a high-level programming language, which means it provides a level of abstraction that is closer to human language & further from machine language. High-level languages like C++ offer several advantages over low-level languages like assembly language:

1. Readability: C++ code is more readable & easier to understand compared to low-level languages. It uses English-like keywords, variables & functions that make the code more intuitive & self-explanatory.

2. Portability: As mentioned earlier, C++ programs can be compiled and run on different platforms with minimal changes to the source code. This portability is possible because C++ abstracts away the low-level details of the hardware and operating system.

3. Faster development: Programming in a high-level language like C++ is generally faster than programming in a low-level language. C++ provides built-in functions, data types, and control structures that simplify the development process and reduce the amount of code needed to accomplish tasks.

4. Easier maintenance: C++ code is easier to maintain and modify than low-level code. Its high-level abstractions and modular design principles make it easier to understand, debug, and update the codebase.

However, don’t think that just because it is a high-level language, C++ takes more resources and compromises on performance. C++ is known for its efficiency and low-level control, allowing developers to write high-performance applications. C++ provides features like pointers, manual memory management, and inline assembly that enable fine-grained control over system resources when needed.

Let’s discuss an example that shows the difference between C++ (high-level) and assembly language (low-level) for a simple task of adding two numbers:

C++:

int a = 10;
int b = 20;
int sum = a + b;

Assembly language (x86):

mov eax, 10
mov ebx, 20
add eax, ebx

As you can see, the C++ code is more readable and concise than the assembly language code.

1. Versatility: C++ is a general-purpose language that can be used to develop a wide range of applications, including system software, device drivers, embedded systems, games, web browsers & more. Its flexibility & power make it suitable for both low-level system programming & high-level application development.

2. Performance: C++ is known for its exceptional performance. It allows developers to have fine-grained control over system resources, enabling them to write highly efficient and optimized code. C++ is often the language of choice for performance-critical applications, such as video games, financial systems, and scientific simulations.

3. Large community & ecosystem: C++ has a large and active community of developers worldwide. This community contributes to the language's growth, provides support, and creates a wealth of libraries, frameworks, and tools that enhance the C++ development experience. The C++ Standard Library, Boost, Qt, and OpenCV are some popular libraries used by C++ developers.

4. Industry adoption: Many major companies and organizations use C++ for their software development needs. Tech giants like Google, Microsoft, Amazon, and Adobe heavily rely on C++ for their core products and services. The gaming industry also extensively uses C++ for game development, with popular game engines like Unreal Engine and Unity supporting C++ programming.

5. Standardization: C++ is an ISO-standardized language, which means it follows a set of well-defined rules and guidelines. The C++ standards committee regularly updates the language to include new features and improvements. This standardization ensures code portability and maintainability across different compilers and platforms.

6. Educational value: C++ is often taught as a fundamental programming language in computer science courses and colleges worldwide. Its core concepts, such as object-oriented programming, pointers, and memory management, provide a strong foundation for learning other programming languages and paradigms.

Let’s look at some of the famous applications and systems developed using C++:

- Operating systems: Windows, macOS & Linux kernels

Web browsers: Google Chrome & Mozilla Firefox
Game engines: Unreal Engine & Unity
Databases: MySQL & MongoDB
Financial systems: Bloomberg & Reuters trading platforms

The popularity of C++ continues to grow as it evolves with new features and improvements. The latest version, C++20, introduces concepts like modules and coroutines, among other enhancements, which make the language even more powerful and expressive.

Case-sensitive

C++ is a case-sensitive language, which means that it distinguishes between uppercase and lowercase letters in identifiers such as variable names, function names, and keywords. This is an important characteristic to keep in mind when writing C++ code.

In C++, the following identifiers are considered unique:

int value;
int Value;
int VALUE;

Each of these variables has a different name and can store a different value. The same applies to function names and other identifiers.

For example:

#include <iostream>

int main() {
    int number = 10;
    int Number = 20;

    std::cout << number << std::endl; 
    std::cout << Number << std::endl; 


    return 0;
}

You can also try this code with Online C++ Compiler

Run Code

Output

10
20

In this code, `number` & `Number` are treated as two separate variables, each holding a different value.

Case sensitivity also applies to keywords in C++. For example, `int`, `if`, `while`, and `return` are keywords that must be written in lowercase. Writing them in uppercase or mixed case will result in a compilation error.

It's important to maintain consistent naming conventions in your C++ code to enhance readability & avoid confusion.

Some common naming conventions are:

camelCase: `myVariable`, `calculateSum`
PascalCase: `MyClass`, `CalculateAverage`
snake_case: `my_variable`, `calculate_product`

This feature of naming convention and sticking to it throughout your codebase helps improve code consistency and makes it easier for other developers to understand and collaborate on your project.

Compiler Based

C++ is a compiled language, which means that developers' source code needs to be compiled before it can be executed. The compilation process translates the human-readable C++ code into machine-readable binary code that can be directly executed by the computer's processor.

The compilation process has many stages, which are:

1. Preprocessing: The preprocessor handles directives like `#include`, `#define`, & conditional compilation statements. It expands macros, includes header files & generates a preprocessed source file.

2. Compilation: The compiler takes the preprocessed source file and translates it into assembly language, a low-level language specific to the target processor architecture. During this stage, the compiler performs syntax analysis, type checking, and optimization.

3. Assembly: The assembler takes the assembly language code generated by the compiler & translates it into machine code, which is a binary representation of the program that can be directly executed by the processor.

4. Linking: The linker combines the compiled object files, along with any necessary libraries, to create an executable file or a library that can be run on the target platform.

Here's a simplified diagram of the C++ compilation process:

Source Code (.cpp) -> Preprocessor -> Compiler -> Assembler -> Linker -> Executable

The compilation process allows C++ programs to be highly optimized for performance. Compilers like GNU C++ Compiler (g++) & Microsoft Visual C++ Compiler (MSVC) offer various optimization flags that can be used to fine-tune the generated code for speed or size.

For example, to compile a C++ source file named `main.cpp` using the GNU C++ Compiler with optimization level 3, you can use the following command:

g++ -O3 main.cpp -o main

This command compiles `main.cpp` with a high level of optimization (`-O3`) & generates an executable file named `main`.

Note: Compiled languages like C++ have many advantages, like faster execution speed and better performance compared to interpreted languages. However, the compilation process adds an extra step in the development workflow, and compiled programs are typically platform-specific, requiring separate builds for different target platforms.

Dynamic Memory Allocation

C++ supports dynamic memory allocation, which allows programs to allocate and deallocate memory at runtime. This feature provides flexibility and efficient memory utilization, especially when dealing with data structures that can grow or shrink during program execution.

In C++, dynamic memory allocation is performed using the `new` & `delete` operators:

- The `new` operator is used to allocate memory dynamically. It returns a pointer to the allocated memory block.

- The `delete` operator is used to deallocate the memory that was previously allocated using `new`.

For example:

#include <iostream>

int main() {
    int* ptr = nullptr;
    int size;

    std::cout << "Enter the number of elements: ";
    std::cin >> size;

    ptr = new int[size];  // Allocate memory dynamically

    std::cout << "Enter " << size << " elements:" << std::endl;
    for (int i = 0; i < size; i++) {
        std::cin >> ptr[i];
    }

    std::cout << "The elements you entered are:" << std::endl;
    for (int i = 0; i < size; i++) {
        std::cout << ptr[i] << " ";
    }

    delete[] ptr;  // Deallocate the memory

    return 0;
}

You can also try this code with Online C++ Compiler

Run Code

Output

Enter the number of elements: 3
Enter 3 elements:
1 45 63
The elements you entered are:
1 45 63

In this example:

1. We declare a pointer `ptr` & an integer `size` to store the number of elements.

2. We prompt the user to enter the number of elements & store it in `size`.

3. We use the `new` operator to allocate memory dynamically for an array of integers with `size` elements.

4. We prompt the user to enter the elements & store them in the dynamically allocated array.

5. We print the elements entered by the user.

6. Finally, we use the `delete[]` operator to deallocate the memory that was allocated dynamically.

Dynamic memory allocation is particularly useful when working with data structures like linked lists, trees, and graphs, where the size of the structure can change during runtime.

However, it's important to note that dynamically allocated memory must be manually deallocated using the `delete` operator to avoid memory leaks. Forgetting to deallocate memory can lead to memory exhaustion & program crashes.

Note: C++11 introduced smart pointers (`std::unique_ptr`, `std::shared_ptr`) that provide automatic memory management and help prevent memory leaks. These smart pointers automatically deallocate memory when it's no longer needed, reducing the chances of memory-related bugs.

Memory Management

C++ provides manual memory management, giving developers fine-grained control over memory allocation and deallocation. This allows for efficient memory usage and optimized performance, but it also places the responsibility of managing memory on the programmer.

In C++, memory is divided into two main regions:

1. Stack: The stack is a region of memory used for storing local variables, function parameters & return addresses. Memory allocation on the stack is automatic & managed by the compiler. When a function is called, its local variables are pushed onto the stack, & when the function returns, the variables are popped off the stack.

2. Heap: The heap is a region of memory used for dynamic memory allocation. Memory on the heap is allocated and deallocated manually by the programmer using the `new` and `delete` operators, respectively. The heap provides a larger pool of memory compared to the stack and allows for dynamic allocation of objects whose size is determined at runtime.

For example:

#include <iostream>

int main() {
    int x = 10;  // Allocated on the stack
    int* ptr = new int(20);  // Allocated on the heap

    std::cout << "Value of x: " << x << std::endl;
    std::cout << "Value pointed by ptr: " << *ptr << std::endl;

    delete ptr;  // Deallocate memory from the heap

    return 0;
}

You can also try this code with Online C++ Compiler

Run Code

Output

Value of x: 10
Value pointed by ptr: 20

In this example:

The variable `x` is allocated on the stack. It is automatically deallocated when the `main()` function returns.
The `ptr` pointer is assigned memory dynamically allocated on the heap using the `new` operator. It needs to be manually deallocated using the `delete` operator to avoid memory leaks.

Proper memory management is crucial in C++ to prevent issues like memory leaks, dangling pointers & memory fragmentation. Memory leaks occur when dynamically allocated memory is not properly deallocated, leading to gradual memory consumption over time. Dangling pointers refer to pointers that point to memory that has already been deallocated, leading to undefined behavior.

To solve these issues, C++ developers should do the following:

Deallocate dynamically allocated memory using `delete` when it is no longer needed.
Use smart pointers (`std::unique_ptr`, `std::shared_ptr`) for automatic memory management.
Avoid excessive dynamic memory allocation & deallocation to minimize memory fragmentation.
Use memory profiling tools to detect & diagnose memory-related issues.

Note: C++11 introduced the concept of RAII (Resource Acquisition Is Initialization), which ties the lifetime of a resource (such as dynamically allocated memory) to the lifetime of an object. This helps ensure that resources are properly acquired & released, reducing the chances of resource leaks.

Multi-threading

C++ supports multi-threading, which allows multiple threads of execution to run concurrently within a single program. Multi-threading enables programs to perform multiple tasks simultaneously, improving performance & responsiveness, especially on systems with multiple cores or processors.

In C++, multi-threading is typically implemented using the C++ Standard Library's `<thread>` header, which provides a high-level interface for creating & managing threads.

Let’s discuss a simple example that shows multi-threading in C++:

#include <iostream>
#include <thread>


void threadFunction(int threadId) {
    std::cout << "Thread " << threadId << " is running." << std::endl;
    // Perform some task
    std::cout << "Thread " << threadId << " has finished." << std::endl;
}

int main() {
    const int numThreads = 5;
    std::thread threads[numThreads];


    // Create and launch multiple threads
    for (int i = 0; i < numThreads; ++i) {
        threads[i] = std::thread(threadFunction, i + 1);
    }

    // Wait for all threads to finish
    for (int i = 0; i < numThreads; ++i) {
        threads[i].join();
    }

    return 0;
}

You can also try this code with Online C++ Compiler

Run Code

In this example:

1. We define a `threadFunction` that takes an integer `threadId` as a parameter. This function represents the task that each thread will execute.

2. In the `main` function, we create an array of `std::thread` objects to store the threads.

3. We use a loop to create & launch multiple threads, each executing the `threadFunction` with a unique `threadId`.

4. After launching the threads, we use another loop to call the `join` function on each thread. This ensures that the main thread waits for all the child threads to finish before proceeding.

When executed, this program will create and run multiple threads concurrently, each performing the task defined in the `threadFunction`. The output will show the threads running and finishing in an interleaved manner.

Multi-threading introduces several challenges, such as synchronization, data sharing, and race conditions. To handle these challenges, C++ provides synchronization primitives like mutexes (`std::mutex`), condition variables (`std::condition_variable`), and locks (`std::lock_guard`, `std::unique_lock`) to ensure thread safety and avoid data races.

Let’s look at an example that shows thread synchronization using a mutex:

#include <iostream>
#include <thread>
#include <mutex>

std::mutex mtx;
int sharedData = 0;

void threadFunction() {
    for (int i = 0; i < 1000; ++i) {
        std::lock_guard<std::mutex> lock(mtx);
        ++sharedData;
    }
}

int main() {
    std::thread t1(threadFunction);
    std::thread t2(threadFunction);


    t1.join();
    t2.join();


    std::cout << "Final value of sharedData: " << sharedData << std::endl;


    return 0;
}

You can also try this code with Online C++ Compiler

Run Code

In this example, we use a mutex (`mtx`) to synchronize access to the `sharedData` variable. Each thread acquires a lock using `std::lock_guard` before modifying `sharedData`, ensuring that only one thread can access it at a time. This prevents data races & ensures thread safety.

Note: Multi-threading is a powerful feature of C++ that enables concurrent execution and improved performance. However, it requires careful design and synchronization to avoid issues like race conditions, deadlocks, and data inconsistencies.

Frequently Asked Questions

Is C++ a case-sensitive language?

Yes, C++ is a case-sensitive language, meaning it distinguishes between uppercase & lowercase letters in identifiers, such as variable names & function names.

What is dynamic memory allocation in C++?

Dynamic memory allocation in C++ allows programs to allocate & deallocate memory at runtime using the `new` & `delete` operators, providing flexibility & efficient memory utilization.

How does C++ support multi-threading?

C++ supports multi-threading through the C++ Standard Library's `<thread>` header, which provides a high-level interface for creating & managing threads, enabling concurrent execution & improved performance.

Conclusion

In this article, we discussed important features of C++, such as object-oriented programming, machine independence, simplicity, high-level abstractions, popularity, case-sensitivity, compilation, dynamic memory allocation, memory management, and multi-threading, which make it one of the most loved and popular programming languages worldwide. These features contribute to C++'s versatility and performance.

You can also check out our other blogs on Code360.

Introduction

Object-Oriented Programming

Machine Independent

Simple

High-Level Language

Popular

Case-sensitive

Compiler Based

Dynamic Memory Allocation

Memory Management

Multi-threading

Frequently Asked Questions

Is C++ a case-sensitive language?

What is dynamic memory allocation in C++?

How does C++ support multi-threading?

Conclusion