C++ and C++: What's the difference?

The difference between C vs. C: Type system: C is weaker, C is stronger and requires explicit conversion. Objects and classes: Not supported by C, supported by C, allowing the creation and use of custom types. Inheritance and polymorphism: Not supported by C, supported by C, allowing class inheritance and reuse features. Function and operator overloading: Not supported by C, supported by C, allowing custom function and operator behavior.

C vs. C: Nuance Analysis

Foreword

C Yes An object-oriented programming language derived from the C language. Despite the similarities, there are important differences between the two languages. This article explores these differences and provides code examples to deepen understanding.

Type system

• C: Use a weaker type system where variables can be implicitly converted to other types.
• C: Has a more robust type system that requires explicit type conversions, thus improving code safety and readability.

// C
int a = 10;
double b = a; // 隐式转换

// C++
int a = 10;
double b = static_cast<double>(a); // 显式转换

Objects and Classes

• C: Object-oriented programming concepts (classes, objects) are not supported.
• C: Supports object-oriented programming, allowing the creation of user-defined types (classes) and instances (objects) from them.

// C++
class Person {
public:
    string name;
};

Person john; // 创建一个 Person 对象
cout << john.name; // 访问对象的成员

Inheritance and polymorphism

• C: Inheritance and polymorphism are not supported.
• C: Supports inheritance and polymorphism, allowing derived classes to inherit the properties and methods of the base class.

// C++
class Employee : public Person {
public:
    int salary;
};

Employee mary; // 创建一个 Employee 对象
cout << mary.name << ", " << mary.salary; // 访问对象属性和方法

Function overloading and operator overloading

• C: Function overloading or operator overloading is not supported.
• C: Supports function overloading (functions with the same name but different parameters) and operator overloading (defining operators for custom types).

// C++
int add(int a, int b); // 函数重载
double operator+(double a, double b); // 运算符重载

Practical case

Consider a program that calculates the average:

C

#include <stdio.h>
int main() {
    int num1, num2;
    printf("Enter two numbers: ");
    scanf("%d %d", &num1, &num2);
    float avg = (num1 + num2) / 2.0;
    printf("Average: %.2f\n", avg);
}

C

#include <iostream>
using namespace std;
int main() {
    int num1, num2;
    cout << "Enter two numbers: ";
    cin >> num1 >> num2;
    double avg = static_cast<double>(num1 + num2) / 2;
    cout << "Average: " << fixed << setprecision(2) << avg << endl;
}

In the C version, explicit type conversion is used to ensure that avg is of type double for accurate averaging value. Additionally, cout and cin are used for input and output, enhancing the user interface.

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