如何在 C++ 函数中实现代码复用和模块化？

int sum(int a, int b) {
  return a + b;
}

struct Person {
  std::string name;
  int age;

  void introduce() {
    std::cout << "My name is " << name << " and my age is " << age << std::endl;
  }
};

#include <iostream>

using namespace std;

// 函数来计算两个数字的平均值
double average(double a, double b) {
  return (a + b) / 2.0;
}

// 类来表示一个学生及其成绩
struct Student {
  string name;
  double gpa;

  // 计算学生的平均成绩
  double calculateAverage() {
    return average(average(gpa1, gpa2), average(gpa3, gpa4));
  }

  // 将学生的姓名和平均成绩打印到控制台
  void print() {
    cout << name << "'s average grade is " << calculateAverage() << endl;
  }

private:
  // 私有成员变量存储四个成绩
  double gpa1, gpa2, gpa3, gpa4;
};

int main() {
  // 创建一个学生对象
  Student student;
  student.name = "John Doe";
  student.gpa1 = 3.5;
  student.gpa2 = 4.0;
  student.gpa3 = 3.7;
  student.gpa4 = 3.8;

  // 打印学生的姓名和平均成绩
  student.print();

  return 0;
}