静态数据成员

#include
using namespace std;
class Student {
private:
	//static int count;
	//在类的声明中，仅对静态数据进行引用性声明，必须在文件作用域的某个地方用类名限定进行定义
	int number;
	char name[20];
	int age;
public:
	static int count;
	Student(const char* n, int a) {
		count = count + 1;
		number = 202000 + count;
		strcpy_s(name, strlen(n) + 1, n);
		age = a;
	}
	void show(void)
	{
		cout << "学号：" << number << endl;
		cout << "姓名：" << name << endl;
		cout << "年龄：" << age << endl;
		cout << "学生总数：" << count << endl;
		cout << "................." << endl;
	}
};

int Student::count = 0;
//静态数据成员不依托具体对象而存在，有自己单独的内存空间
//当静态数据成员是被声明为public时，可以通过类名直接对他进行访问
int main() {

	Student s1("张三",21);
	Student s2("李四",22);
	Student s3("王五",23);
	s1.show();
	s2.show();
	s3.show();
	cout << Student::count;

	return 0;
}