C++——面对对象（基本用法）

类的定义

class 类名{

????????访问权限:

????????????????属性;

????????????????方法;

}

类的调用

????????类名 对象名；

????????对象名.方法名();

????????对象名.属性名;

示例代码一：?计算圆周长/面积

#define PI 3.14

class Circle {
    public:
        float radius;
        // 获取周长
        float get_ZC(){
            return 2*PI*radius;
        }
        //获取圆的面积
        float get_area(){
            return radius*radius*PI;
        }
};

int main(){
    Circle c1;
    c1.radius = 10.5;
    float zc,area;
    zc = c1.get_ZC();
    area = c1.get_area();
    cout<<"周长:"<< zc<<","<<"面积:"<<area <<endl; //周长:65.94,面积:346.185
}

示例代码二： 设计学生类修改姓名/电话

class Student{
    public:
        string s_name;
        int s_age;
        int s_gender=0;
    private:
        string s_phone_number;
    public:
        void set_name(string name,int age,string phone_number){
            s_name = name;
            s_age = age;
            s_phone_number=phone_number;
            cout<<"name:"<<s_name<<endl;
            cout<<"age:"<<s_age<<endl;
            cout<<"phone_number:"<<s_phone_number<<endl;
        }
};

int main(){
    Student s;
    s.set_name("yoyo", 20, "13500000000");
    return 1;
}