学习记录——C++
定义一个学生类Student,包括3个数据成员:学号id,姓名name,分数score;两个静态数据成员:总分total和学生人数count;带参数的构造函数用来初始化对象,成员函数ChangeScore用来修改分数,静态成员函数GetAverage用来打印计算得到的平均分
我的第一篇博客
C++学习记录
#include <iostream>
#include <string>
using namespace std;
class Student
{
public:
Student(int id,string name,double score):id(id),name(name),score(score) //带参数的构造函数初始化对象
{
count++;
total+=score;
}
void ChangeScore(double newScore)
{
total+=newScore-score; //因为是静态,所以定义一个新变量newScore
score=newScore;
}
static double GetAverage()
{
return total/count;
}
private:
int id;
string name;
double score;
static double total;
static int count;
};
double Student::total=0.0f;
int Student::count=0; // 类外对静态数据成员进行定义声明
int main()
{
Student s1(01,"Wang",78);
Student s2(02,"Liu",85);
Student s3(03,"Chen",90);
cout<<"The average score is:"<<Student::GetAverage()<<endl;
s1.ChangeScore(82);
s2.ChangeScore(85);
s3.ChangeScore(76);
cout<<"The new average score is:"<<Student::GetAverage()<<endl;
}
运行结果: