C + + Exception Class (Exception classes) detailed

The Anomaly class (exception classes) consists of 4 base classes, Bad_cast, Bad_alloc,runtime_error, Logic_error;

Runtime_error: Errors can be detected only when the program is running;

Logic_error: A logic error detected by the application.

Where Bad_cast, Bad_alloc uses the default constructor, Runtime_error, Logic_error, must be initialized with a string (C-style or STL);

User-defined classes can also inherit (inherit) from the exception class and initialize the corresponding parameters;

The code is as follows:

* * * cppprimer.cpp * * Created on:2013.11.28 * author:caroline//*eclipse CDT, gcc 4.8.1*/ /* setlocale Example * * #include <iostream> #include <string> #include <stdexcept> usin  
      
G namespace Std;  Class Out_of_stock:public Std::runtime_error {public://Initialize Runtime_error explicit out_of_stock of the base class (const  
      
std::string &s): Std::runtime_error (s) {}}; Class Id_mismatch:public Std::logic_error {public:explicit id_mismatch (const std::string &s): Std::logi  
        C_error (s) {} id_mismatch (const std::string &s, const std::string &AMP;LHS, const std::string &AMP;RHS):  
Std::logic_error (s), left (LHS), right (RHS) {} const std::string left, right;  
      
}; struct My_food {my_food (const std::string FI, const int fn): food_id (FI), Food_num (FN) {} my_food& Ope  
    rator+= (const my_food& RHS);  
    Std::string food_id; int food_num;  
}; my_food& my_food::operator+= (const my_food& RHS) {if (this->food_id!= rhs.food_id) throw id_  
    Mismatch ("Wrong id", this->food_id, rhs.food_id);  
    This->food_num + = Rhs.food_num;  
return *this;  
    int main (void) {My_food M1 ("Apple", 3), M2 ("Pear", 2), M3 ("Apple", 2);  
        try{M1 + = M3;  
        Std::cout << m1.food_id << ":" << m1.food_num << Std::endl;  
    M1 + = M2; }catch (const Id_mismatch &e) {std::cerr << e.what () << ": Left ID (" << e.l  
    EFT << ") Right ID (" << e.right << ")" << Std::endl; }  
}

Output:

Apple:5  
wrong Id:left ID (Apple) Right ID (Pear)

Author: csdn Blog spike_king

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