20251121学习指针
int a = 5;
cout << "a=" << a << endl;
// & 取地址符,用来取出变量的地址
cout << "变量a的地址是:" << &a << endl;
int* p;
p = &a;
cout << "p的值是:" << p << endl ;
int b = 6;
p = &b;
cout << *p << endl; //*p,就找到他指向变量的值
*p = 7;
cout << b << endl;