Shulou(Shulou.com)06/02 Report--

This article mainly explains "how to use the C++ constructor". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought. Let's study and learn how to use the C++ constructor.

Like structures, we can initialize them using the list initialization method:

Struct Thing {char * pn; int m;}; Thing th = {"hello", 23}

But the class is not, because the member variables in the structure are public, and the class is often private. This means that we can't access the data members directly with the program, we need to design them as functions.

In C++, the function used to construct a class is called a class constructor. The prototype and header of the constructor have an obvious feature-although it does not return a value, it is not declared as a void type. In fact, the constructor does not declare a type.

For example, we are still the previous class:

Class Stock {private: std::string company; long shares; double share_val; double total_val; void set_tot () {total_val = shares * share_val;} public: void accquire (const std::string & co, long n, double pr); void buy (long num, double price); void sell (long num, double price); void update (double price); void show ();}; # endif

Now we are going to add the constructor, first by adding a declaration to the class:

Class Stock {... Stock (const string & co, long nasty 0, double pr=0.0);}

Notice that when we implement the definition, the function has no return type:

Stock::Stock (const string & co, long n, double pr) {company = co; if (n < 0) {std::cerr

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.