C++ vs C

C is primarily a procedural programming language, while C++ supports procedural programming as well as object-oriented and generic programming.

C  → Procedural Programming

C++ → Procedural + Object-Oriented + Generic Programming

C was developed before C++. C++ was developed as an extension of the C programming language.

The early version of C++ was known as C with Classes.

C mainly follows a procedural programming approach. Programs are organized around functions and procedures.

C++ supports multiple programming approaches, including:

• Procedural programming
• Object-oriented programming
• Generic programming

C does not provide classes as a built-in language feature. C++ provides classes for creating user-defined types.

class Student {
public:
    int age;
};

C++ allows programmers to create objects from classes.

class Student {
public:
    int age;
};

int main() {

    Student s1;

    s1.age = 20;

    return 0;
}

The object s1 is an instance of the Student class.

C++ provides built-in language features for object-oriented programming. Important concepts include:

• Classes
• Objects
• Encapsulation
• Inheritance
• Polymorphism
• Abstraction

C does not provide these concepts as built-in object-oriented language features.

C++ supports encapsulation through classes and access specifiers such as private, protected, and public.

class Account {

private:
    double balance;

public:
    void setBalance(double amount) {
        balance = amount;
    }
};

C++ supports inheritance, which allows one class to derive from another class.

class Animal {
};

class Dog : public Animal {
};

Inheritance is a built-in C++ class feature.

C++ supports polymorphism through features such as function overloading and virtual functions.

void display(int x) {
}

void display(double x) {
}

This is an example of function overloading in C++.

C++ allows multiple functions with the same name when their parameter lists are different.

void add(int a, int b) {
}

void add(double a, double b) {
}

Function overloading is supported by C++ but is not a feature of C.

C++ supports operator overloading for user-defined types. This allows operators to be given appropriate behavior for class objects.

For example, a class can define how the + operator works with its objects.

C++ supports templates for generic programming. Templates allow functions and classes to work with different data types.

template <typename T>
T maximum(T a, T b) {
    return (a > b) ? a : b;
}

Templates are an important feature of C++.

C commonly uses functions such as printf() and scanf() for standard input and output.

C++ commonly uses stream objects such as std::cout and std::cin.

// C++
#include <iostream>

std::cout << "Hello";
std::cin >> value;

Both C and C++ use header files, but their standard libraries provide different headers and facilities.

C example:

#include <stdio.h>

C++ example:

#include <iostream>

#include <stdio.h>

int main() {

    int age;

    printf("Enter age: ");
    scanf("%d", &age);

    printf("Age = %d", age);

    return 0;
}

#include <iostream>

int main() {

    int age;

    std::cout << "Enter age: ";
    std::cin >> age;

    std::cout << "Age = " << age;

    return 0;
}

Both languages provide low-level memory management capabilities. C commonly uses malloc(), calloc(), realloc(), and free().

C++ provides new and delete, along with modern smart pointers such as std::unique_ptr and std::shared_ptr.

Both C and C++ support structures, but their language rules differ. C++ structures can contain member functions and support features associated with classes.

struct Student {

    int age;

    void show() {
        std::cout << age;
    }
};

C++ provides references as a language feature. A reference acts as another name for an existing object or variable.

int number = 10;

int& ref = number;

ref = 20;

References are not part of the C language.

C++ provides built-in exception handling using try, catch, and throw.

try {
    // Code
}
catch (...) {
    // Handle exception
}

C does not provide this C++ exception-handling mechanism.

Both C and C++ provide standard libraries, but C++ has a much broader set of standard library facilities, including containers, algorithms, iterators, strings, and other utilities.

The C++ Standard Template Library is commonly known as STL.

C++ provides standard containers such as:

• vector
• list
• deque
• map
• set
• queue
• stack

#include <vector>

std::vector<int> numbers = {10, 20, 30};

C commonly represents text using character arrays. C++ provides the std::string class as part of its standard library.

#include <string>

std::string name = "Rahul";

The C++ string class provides many convenient operations for handling text.

Many basic statements look similar in C and C++. For example, variables and control statements use familiar syntax.

int age = 20;

if (age >= 18) {
    // Code
}

However, C++ adds many additional language features.

Both C and C++ can produce highly efficient compiled programs. Performance depends on the implementation, compiler, algorithms, data structures, and how the program is written.

C++ provides additional abstractions while also allowing low-level programming techniques.

C is widely used in areas such as:

• Operating-system components
• Embedded systems
• System programming
• Device software
• Low-level software

C++ is used in many areas, including:

• Game development
• Game engines
• Desktop applications
• System software
• Graphics applications
• Embedded software
• High-performance applications

Learning C helps students understand procedural programming, memory, pointers, arrays, functions, and low-level programming concepts.

Learning C++ builds on many of these concepts and adds object-oriented, generic, and modern programming features.

A learner who understands the fundamentals of C can recognize many familiar concepts when beginning C++.

C and C++ share many fundamental concepts, but C++ extends the programming model with classes, objects, inheritance, polymorphism, templates, references, exception handling, and a large standard library.

C
↓
Procedural Programming
↓
Functions + Structures + Pointers

C++
↓
Procedural Programming
+
Object-Oriented Programming
+
Generic Programming
+
Standard Library

Understanding the differences between C and C++ will make it easier to understand why C++ provides additional programming techniques while retaining many familiar C-style concepts.