静态成员函数(Static member functions) 只可以使用静态成员的场景 代码示例 总结 基本概念 引例:银行账户类中需要一个数据成员来表示利率,利率变动时,所有的对象都用新的利率,利率是和类相关联而不和每个对对象关联,此时利率便适合作为静态成员。 classAccount{public:staticvoidSetInterestRate(doublenew_interest_rate...
We can do better. In this case, the answer to the problem is that we can also make member functions static. Like static member variables, static member functions are not attached to any particular object. Here is the above example with a static member function accessor: 1 2 3 4 5 6 7...
You can call a static member function using thethispointer of a nonstatic member function. In the following example, the nonstatic member functionprintall()calls the static member functionf()using thethispointer: #include <iostream> using namespace std; class C { static void f() { cout <...
在引入static member functions之前,C++语言要求所有的member functions都必须经由该class的object来调用。而实际上,只有当一个或多个nonstatic data members在member function中被直接存取时,才需要class object。Class object提供了this指针给这种形式的函数调用使用。这个this指针把“在member functiong中存取的nonstatic c...
对于static member functions而言,它们与static member variables类似,它们是该类所有对象公有的。因为对象需要创建才存在,而non- static member是和object绑定的。所以static member functions禁止访问non-static member (neither member variables nor member functions),当然也无法在函数内部使用this关键字。
好多人喜欢把工具函数做成static member function。这样以增加隐蔽性和封装性,由其是从C#,java转而使用c++的开发人员。 例如: class my_math { public: static UINT Hash_XYZ(float x,float y,float z); static UINT Hash_XY(floag t, float y); ...
error: invalid use of non-static member function ‘bool MyClass::cmp(int, int)’ 看报错信息的字面意思似乎是:因为cmp是非static函数,那如果把cmp定义成static呢?果然编译ok。这是为啥? 这就涉及到第一个问题:static成员函数和非static成员函数有什么区别?
浅出理解静态成员函数(static member function) 2017-08-18 16:00 −转自:http://blog.csdn.net/danky/article/details/1447011 在转入正题之前,我觉得应该先提出两个我本人自定义的术语:类级成员(class level member)和对象级成员(object level member)。我不知道在C++领域里是否已经有... ...
A static member function cannot access the non static members of the class or base classclass X{ public: int b; static int a; enum mode{a1,a2,a3}; static int inc() { return b;//this will give an error } X(){}; }; Static data members of class have extern linkage, they can ...
error C2597:illegal reference to data member'Point::m_x'inastaticmemberfunction 因为静态成员函数属于整个类,在类实例化对象之前就已经分配空间了,而类的非静态成员必须在类实例化对象后才有内存空间,所以这个调用就出错了,就好比没有声明一个变量却提前使用它一样。