在C++中無法找到段錯誤錯誤

Question

我有3個C++文件，instrument.h, percussion.h, and instrumentApp.cpp。 Instrument.h是基類，percussion.h繼承它。 Percussion對象在instrumentApp.cpp類中定義和實現。每當我運行instrumentApp.cpp時，我都會遇到分段錯誤錯誤。

我已經設法追查錯誤的原因，以函數中的超載<< operator函數，我在這裏調用基類instrument.h的方法。出於某種原因，我的代碼無法調用基類的方法，我不知道爲什麼。你能幫我麼？

這裏是instrument.h類

#ifndef INSTRUMENT_H 
#define INSTRUMENT_H 


class Instrument{ 
     private: 
       std::string name; 
       std::string sound; 
       std::string lowRange; 
       std::string highRange; 
     public: 
       Instrument(std::string name, std::string sound, std::string lowRange, std::string highRange){ 
         this->name = name; 
         this->sound = sound; 
         this->lowRange = lowRange; 
         this->highRange = highRange; 
       } 

       std::string getName() const{ 
         return this->name; 
       } 

       std::string play()const { 
         return this->sound; 
       } 

       std::string getLowRange() const{ 
         return this->lowRange; 
       } 

       std::string getHighRange() const{ 
         return this->highRange; 
       } 

       bool isWind(); 
       bool isWoodWind(); 
       bool isBrass(); 
       bool isKeyboard(); 
       bool isPercussion(); 
       bool isStrings(); 

       friend std::ostream &operator <<(std::ostream &os, const Instrument &instrument){ 
       } 
}; 

#endif 

這裏是percussion.h類

#ifndef PERCUSSION_H 
#define PERCUSSION_H 

#include "instrument.h" 

class Percussion : public Instrument{ 
     private: 
       bool struck; 
     public: 
       Percussion(std::string name, std::string sound, std::string lowRange, std::string highRange, bool struck) : Instrument(name,sound,lowRange,highRange){ 
         this->struck=struck; 

       } 

       bool isStrucked() const { 
         return this->struck; 
       } 

       bool isPercussion() { 
         return true; 
       } 

       std::string getType() const{ 
         if(this->struck){ 
           return "struck"; 
         } 
         else{ 
           return ""; 
         } 
       } 

       friend std::ostream &operator <<(std::ostream &os, Percussion &percussion){ 
      //The error stems from this line of code 
      //Apparently, the getName() method in the base class isn't called 

          os<<percussion.getName(); 

       } 

}; 

#endif 

這裏是實現文件instrumentApp.cpp

#include <iostream> 
#include <string> 
#include <sstream> 
#include <cstdlib> 

#include "instrument.h" 

#include "percussion.h" 
#include "strings.h" 

using namespace std; 



int main() { 

    Percussion timpani("timpani", "boom", "D2", "A2", true); 
    cout << timpani << endl; 

    Percussion harp("harp", "pling", "Cb1", "F#7", false); 
    cout << harp << endl; 

    return 0; 
} 

Answer 1

這裏的問題是，當我超載<時，我沒有返回os對象運營商。

解決方法是作爲percussion.h文件

friend std::ostream &operator <<(std::ostream &os, Percussion &percussion){ 

     os<<percussion.getName(); 

     return os; 

}