对象 1 作用域解析符 ：：

1 对象举例
#include <iostream>
using namespace std;
class Car {
public:
    string color;
    string engine;
    float gas_tank;
    unsigned int wheel;

    void running(void);
};

void Car::running(void){    //作用域解析符，方法属于哪个类
    cout << "run run run" << endl;
}

int main() {
    Car car;
    car.running();
    return 0;
}
/* vim: set ts=4 sw=4 sts=4 tw=100 */

注意事项：

1 类的声明 。h 文件中    类的函数的定义放入 cpp 中

2 c++允许在类里面声明常量，但不允许对它进行赋值。
class Car
{
public:
     const float TANKSIZE = 85;  //出错
     static const float TANKSIZE = 85; //ok

} 

3 a = b 是完全复制 

#include <iostream>
using namespace std;
class Car {
public:
    string color;
};


int main() {

    Car car1, car2;
    car1.color = "red";

    car2 = car1;

    cout << "car1.color = red" << endl;

    cout << "car2 = car1 , car2 color " << car2.color << endl;

    car2.color = "blue";

    cout << "change car2 , look car1 " << car1.color << endl;

    return 0;
}
/* vim: set ts=4 sw=4 sts=4 tw=100 */