Question

该代码由四部分组成。其中一个是DVD类，其他的是HarryPotterDVD.h，HarryPotterDVD.cpp和HarryPotterDVDDriver.cpp。当我编译代码时，它在编译时不会给我任何错误，但是当我尝试运行已编译的可执行文件时，出现了Abort（核心转储）错误。我认为这是因为我使用继承函数的方式。你们可以帮我弄清楚如何解决问题。

DVD.cpp

/admin/application_settings/network

HarryPotterDVD.h

#include "DVD.h"

DVD::DVD() {
    id =0;
    title = new char[1];
    title[0] = '\0';
    director = new char[1];
    director[0] = '\0';
}

DVD::DVD(unsigned int i, const char* t, const char* dir) {
    id = i;
    int len;
    for(len = 0; t[len] !='\0'; ++len);
    title = new char[len+1];
    for(int i = 0; i < len+1; i++) {title[i]=t[i];}

    int len2;
    for(len2=0; dir[len2] !='\0'; ++len2);
    director = new char[len2+1];
    for(int j = 0; j<len2+1; j++) {director[j] = dir[j];}
}

DVD::DVD(const DVD &d): id(d.id) {
    int len;
    for(len=0; d.title[len] !='\0'; ++len);
    title = new char[len+1];
    for(int j = 0; j < len+1; j++) {
        title[j] = d.title[j];
    }

    int len2;
    for(len2=0; d.director[len2] != '\0'; ++len2);
    director = new char[len2+1];
    for(int j = 0; j<len2 +1; j++) {
        director[j] = d.director[j];
    }
}

DVD::~DVD() {
    if (title) {
        delete [] title;
    }
    if (director) {
        delete [] director;
    }
}

int DVD::getID() {
    return id;
}

char* DVD::getTitle() {
    return title;
}

char* DVD::getDirector() {
    return director;
}

void DVD::display() {
    cout << '[' << id << '.' << ' ' << title << '/' << director << ']' << endl;
}

void DVD::setID(unsigned int i) {
    id = i;
}

void DVD::setTitle(const char* t) {
    delete [] title;
    int len;
    for(len = 0; t[len] !='\0'; ++len);
    title = new char[len+1];
    for(int i = 0; i < len+1; i++) {title[i]=t[i];}
}

void DVD::setDirector(const char* dir) {
    delete [] director;
    int len2;
    for(len2=0; dir[len2] !='\0'; ++len2);
    director = new char[len2+1];
    for(int j = 0; j<len2+1; j++) {director[j] = dir[j];}    
}

DVD& DVD::operator= (const DVD& arg) {
    id = arg.id;

    int len;
    for(len = 0; arg.title[len] !='\0'; ++len);
    title = new char[len+1];
    for(int i = 0; i < len+1; i++) {title[i]=arg.title[i];}

    int len2;
    for(len2=0; arg.director[len2] !='\0'; ++len2);
    director = new char[len2+1];
    for(int j = 0; j<len2+1; j++) {director[j] = arg.director[j];}  
    return *this;
}

HarryPotterDVD.cpp

#ifndef _HarryPotterDVD_
#define _HarryPotterDVD_
#include<iostream>
#include "DVD.h"
using namespace std;

class HarryPotterDVD : public DVD {
        int episode;
        char * antagonist;
    public:
        HarryPotterDVD(unsigned int i, char* t, char* dir, int n, char* ant);
        HarryPotterDVD();
        HarryPotterDVD(HarryPotterDVD& d);
        ~HarryPotterDVD();
        int getEpisode();
        char* getAntagonist();
        void display();
        void setEpisode(unsigned int e);
        void setAntagonist(const char* c);
        HarryPotterDVD& operator= (HarryPotterDVD& arg);
};
#endif

HarryPotterDVDDriver.cpp

#include "HarryPotterDVD.h"
#include<iostream>
using namespace std;

HarryPotterDVD::HarryPotterDVD(unsigned int i, char* t, char* dir, int n, char* ant): DVD( i , t , dir) {
    episode = n;
    int len;
    for(len = 0; ant[len] !='\0'; ++len);
    antagonist = new char[len+1];
    for(int j = 0; j < len+1; j++) {antagonist[j]=ant[j];}
}

HarryPotterDVD::HarryPotterDVD(HarryPotterDVD &d) {
    DVD::setID(d.DVD::getID());
    DVD::setTitle(d.DVD::getTitle());
    DVD::setDirector(d.DVD::getDirector());
    episode = d.episode;
    int len;
    for(len = 0; d.antagonist[len] != '\0'; len++);
    antagonist = new char[len + 1];
    for(int i = 0; i < len; i++){
        antagonist[i] = d.antagonist[i];
    }
    antagonist[len+1] = '\0';
}

HarryPotterDVD::HarryPotterDVD() {
    episode = -1;
    char* tmp = "";
    antagonist = tmp;
}

HarryPotterDVD::~HarryPotterDVD(){
    delete [] antagonist;
}

int HarryPotterDVD::getEpisode(){
    return episode;
}

char * HarryPotterDVD::getAntagonist(){
    return antagonist;
}

void HarryPotterDVD::display(){
    cout << "[" << DVD::getID() << ". HP" << episode;
    cout << ":" << DVD::getTitle() << "/" << DVD::getDirector();
    cout << "/" << antagonist << "]" << endl; 
}

void HarryPotterDVD::setEpisode(unsigned int e){
    episode = e;
}

void HarryPotterDVD::setAntagonist(const char * c){
    delete [] antagonist;
    int len;
    for(len = 0; c[len] != '\0'; len++);
    antagonist = new char[len + 1];
    for(int i = 0; i < len; i++){
        antagonist[i] = c[i];
    }
    antagonist[len+1] = '\0';
}

HarryPotterDVD& HarryPotterDVD::operator= (HarryPotterDVD &d){
    delete [] antagonist;
    episode = d.episode;

    int len3;
    for(len3 = 0; d.antagonist[len3] != '\0'; len3++);
    antagonist = new char[len3 + 1];
    for(int i = 0; i < len3; i++){
        antagonist[i] = d.antagonist[i];
    }
    antagonist[len3+1] = '\0';
    DVD::operator=(d);
    /*
    setID(d.getID());
    int len;
    for(len = 0; d.getTitle()[len] != '\0'; len++);
    char * tit = new char[len+1];
    for(int i = 0; i < len; i++){
        tit[i] = d.getTitle()[i];
    }
    tit[len] = '\0';
    setTitle(tit);
    int len2;
    for(len2 = 0; d.getDirector()[len2] != '\0'; len2++);
    char* dire = new char[len2+1];
    for(int i = 0; i < len2; i++){
        dire[i] = d.getDirector()[i];
    }
    dire[len2] = '\0';
    setDirector(dire);
    */
    return* this;
}

Answer 1

在HarryPotterDVD的默认构造函数中，您正在向成员变量antagonist分配一个随机指针，该成员变量不是用new[]创建的

HarryPotterDVD::HarryPotterDVD() {
    episode = -1;
    char* tmp = "";
    antagonist = tmp;
}

在operator=()函数中，当执行语句h1=h3;时，您正在使用antagonist删除delete[]，这会导致分段错误。

delete是null安全的。因此，在您的默认构造函数中，您只需在分配期间将它们的nullptr和delete的指针指向它们就不会引起任何错误。如果您以这种方式进行更改，那么您的问题应该会消失。

HarryPotterDVD::HarryPotterDVD() {
    episode = -1;
    antagonist = nullptr;

}

尝试编译代码时出现Abort（核心转储）错误

1 个答案: