对不起，我知道这是Stack Overflow上的第十九段错误帖子，但我已经尝试了几天修复这段代码而且我很难过，所以我决定转向你们。我希望你能帮忙！
无论如何，我在这段代码中得到了一个奇怪的段错误：
account.h（注意，根据作业，我不允许以任何方式修改account.h文件。）
class account
{
public:
typedef char* string;
static const size_t MAX_NAME_SIZE = 15;
// CONSTRUCTOR
//account();
account (char* i_name, size_t i_acnum, size_t i_hsize);
account (const account& ac);
// DESTRUCTOR
~account ( );
// MODIFICATION MEMBER FUNCTIONS
void set_name(char* new_name);
void set_account_number(size_t new_acnum);
void set_balance(double new_balance);
void add_history(char* new_history);
// CONSTANT MEMBER FUNCTIONS
char* get_name () const;
size_t get_account_number ( ) const;
double get_balance( ) const;
size_t get_max_history_size( ) const;
size_t get_current_history_size ( ) const;
string* get_history() const;
friend std::ostream& operator <<(std::ostream& outs, const account& target);
private:
char name[MAX_NAME_SIZE+1]; //name of the account holder
size_t ac_number; //account number
double balance; //current account balance
string* history; //Array to store history of transactions
size_t history_size; //Maximum size of transaction history
size_t history_count; //Current size of transaction history
};
account.cxx：
#include <string.h>
#include <cassert>
#include <cstdlib>
#include <iostream>
#include "account.h"
using namespace std;
account::account(char* i_name, size_t i_acnum, size_t i_hsize)
{
assert(strlen(i_name) <= MAX_NAME_SIZE);
strcpy(name, i_name);
ac_number = i_acnum;
history_size = i_hsize;
balance = 0;
history_count = 0;
history = new string[history_size];
}
account::account(const account& ac)
{
strcpy(name, ac.name);
ac_number = ac.ac_number;
balance = ac.balance;
history = new string[ac.history_size];
for(size_t i = 0; i < ac.history_count; i++)
{
history[i] = new char[strlen(ac.history[i]) + 1];
strcpy(history[i], ac.history[i]);
}
history_count = ac.history_count;
history_size = ac.history_size;
}
account::~account()
{
delete[] history;
}
void account::set_name(char* new_name)
{
assert(strlen(new_name) <= MAX_NAME_SIZE);
strcpy(name, new_name);
}
void account::set_account_number(size_t new_acnum) {ac_number = new_acnum;}
void account::set_balance(double new_balance) {balance = new_balance;}
void account::add_history(char* new_history)
{
assert(history_count < history_size);
history[history_count] = new char[strlen(new_history) + 1];
strcpy(history[history_count], new_history);
history_count++;
}
char* account::get_name() const
{
char* blah = new char[MAX_NAME_SIZE + 1];
strcpy(blah, name);
return blah;
}
size_t account::get_account_number ( ) const {return ac_number;}
double account::get_balance( ) const{return balance;}
size_t account::get_max_history_size( ) const {return history_size;}
size_t account::get_current_history_size ( ) const {return history_count;}
account::string* account::get_history() const
{
string* blah = new string[history_size];
for(size_t i = 0; i < history_count; i++)
{
blah[i] = new char[strlen(history[i]) + 1];
strcpy(blah[i], history[i]);
}
return blah;
}
std::ostream& operator<< (std::ostream& outs, const account& target)
{
outs << "Name: " << target.name << "\n"
<< "Account Number: " << target.ac_number << "\n"
<< "Balance: " << "$" << target.balance << "\n"
<< "History: ";
for(size_t i = 0; i < target.history_count; i++)
{
outs << target.history[i] << "\n";
}
outs << "Current History Size: " << target.history_count << "\n";
outs << "Max History Size: " << target.history_size << "\n";
return outs;
}
bankledger.h
class bank_ledger
{
public:
static const int MAX_ACC_SIZE = 15;
bank_ledger(int mo, int mc);
bank_ledger(const bank_ledger& copyledger);
~bank_ledger();
void create_account(char* i_name, size_t i_acnum, size_t i_hsize);
void close_account(double accnum);
double balance_of(double accnum);
void deposit(double accnum, double money);
void withdraw(double accnum, double money);
void transfer(double accnum1, double accnum2, double money);
void print_account_history(double accnum);
void print_account_details(double accnum);
void print_current_details();
void print_closed_details();
account* lookup(double accnum);
private:
account** open;
account** closed;
int max_open;
int max_closed;
int num_open;
int num_closed;
};
bankledger.cxx：
#include <cstdlib>
#include <iostream>
#include <cassert>
#include "account.h"
#include "bank_ledger.h"
using namespace std;
bank_ledger::bank_ledger(int mo = 30, int mc = 30)
{
max_open = mo;
max_closed = mc;
open = new account*[max_open];
closed = new account*[max_closed];
num_open = 0;
num_closed = 0;
}
bank_ledger::bank_ledger(const bank_ledger& copyledger)
{
int i;
max_open = copyledger.max_open;
max_closed = copyledger.max_closed;
num_open = copyledger.num_open;
num_closed = copyledger.num_closed;
open = new account*[num_open];
closed = new account*[num_closed];
for(i = 0; i < max_open; i++)
{
if (i < num_open)
open[i] = copyledger.open[i];
}
for(i = 0; i < max_closed; i++)
{
if (i < num_closed)
closed[i] = copyledger.closed[i];
}
}
bank_ledger::~bank_ledger()
{
for(int i = 0; i < num_open; i++)
{
delete open[i];
}
for(int i = 0; i < num_closed; i++)
{
delete closed[i];
}
delete[] open;
delete[] closed;
}
account* bank_ledger::lookup(double accnum)
{
for(int i = 0; i < num_open; i++)
{
if(open[i]->get_account_number() == accnum)
{
return *open + i;
}
if(closed[i]->get_account_number() == accnum)
{
return *closed + i;
}
}
}
void bank_ledger::create_account(char* i_name, size_t i_acnum, size_t i_hsize)
{
assert(num_open < max_open);
open[num_open] = new account(i_name, i_acnum, i_hsize);
open[num_open]->add_history("Account Created");
num_open++;
}
void bank_ledger::close_account(double accnum)
{
int i;
double temp = -1;
cout << *(open[0]) << endl << "Good Idea" << endl;
account* acc = lookup(accnum);
for(i = 0; i < num_open; i++)
{
if(open[i]->get_account_number() == acc->get_account_number())
{
temp = i;
closed[num_closed] = open[i];
for(i = temp; i < num_open - 1; i++)
{
open[i] = open[i+1];
}
closed[num_closed]->add_history("Account Closed");
num_open--;
num_closed++;
return;
}
}
}
double bank_ledger::balance_of(double accnum)
{
return lookup(accnum)->get_balance();
}
void bank_ledger::deposit(double accnum, double money)
{
account* acc = lookup(accnum);
acc->set_balance(acc->get_balance() + money);
acc->add_history("Deposited $");
}
void bank_ledger::withdraw(double accnum, double money)
{
account* acc = lookup(accnum);
acc->set_balance(acc->get_balance() - money);
acc->add_history("Withdrew $");
}
void bank_ledger::transfer(double accnum1, double accnum2, double money)
{
withdraw(accnum2, money);
deposit(accnum1, money);
}
void bank_ledger::print_account_history(double accnum)
{
account* acc = lookup(accnum);
account::string *hist = acc->get_history();
cout << "History of " << acc->get_name() << "'s account: " << endl;
for (int i = 0; i < acc->get_current_history_size(); i++) cout << hist[i] << endl;
}
void bank_ledger::print_account_details(double accnum)
{
account* acc = lookup(accnum);
cout << *acc;
cout << "\n";
}
void bank_ledger::print_current_details()
{
for(int i = 0; i < num_open; i++)
{
cout << *open[i] << "\n";
}
}
void bank_ledger::print_closed_details()
{
for(int i = 0; i < num_closed; i++)
{
cout << *closed[i] << "\n";
}
cout << "\n";
}
sample_test_input2.cxx
#include <cstdlib>
#include <iostream>
#include "account.h"
#include "bank_ledger.h"
using namespace std;
int main()
{
bank_ledger bl(30, 30);
bl.create_account("name1", 1, 30);
bl.create_account("name2", 2, 30);
bl.create_account("name3", 3, 30);
bl.create_account("name4", 4, 30);
bl.print_current_details();
bl.close_account(2);
return 0;
}
Valgrind和GDB都说*（open [i]）未初始化。这是Valgrind的确切输出：
==7082== Use of uninitialised value of size 8
==7082== at 0x1000018C6: account::get_account_number() const (account.cxx:74)
==7082== by 0x10000246B: bank_ledger::lookup(double) (bank_ledger.cxx:85)
==7082== by 0x1000027D0: bank_ledger::close_account(double) (bank_ledger.cxx:105)
==7082== by 0x100003117: main (sample_test_input2.cxx:17)
==7082==
==7082== Invalid read of size 8
==7082== at 0x1000018C6: account::get_account_number() const (account.cxx:74)
==7082== by 0x10000246B: bank_ledger::lookup(double) (bank_ledger.cxx:85)
==7082== by 0x1000027D0: bank_ledger::close_account(double) (bank_ledger.cxx:105)
==7082== by 0x100003117: main (sample_test_input2.cxx:17)
==7082== Address 0x10 is not stack'd, malloc'd or (recently) free'd
它从主要地方转移到bankledgrer::close_account，再转移到bankledger::lookup，然后它在if(open[i]->get_account_number() == accnum)
如果我在该行之前粘贴cout << *(open[i])，则会将其打印出来。
我担心我不知所措。任何帮助，将不胜感激。如果您希望我包含头文件或澄清任何内容，请告诉我。
PS。另外，我知道这段代码非常C，但这就是我教授想要它的方式，即使它是一个C ++类。去搞清楚。 ：\
答案 0 :(得分：4)
在这种方法中：
account* bank_ledger::lookup(double accnum)
{
for(int i = 0; i < num_open; i++)
{
if(open[i]->get_account_number() == accnum)
{
return *open + i;
}
if(closed[i]->get_account_number() == accnum)
{
return *closed + i;
}
}
}
您假设至少与未结账户金额相同的已结账户数量。你应该在不同的循环中迭代打开和关闭的数组，因为你试图访问closed [i]，i = 1,2,3 ......，而closed不包含任何有效的指针（只是一堆NULL指针）。这应该有用（除非我遗漏了别的东西）：
account* bank_ledger::lookup(double accnum) {
for(int i = 0; i < num_open; i++) {
if(open[i]->get_account_number() == accnum)
return open[i];
}
for(int i = 0; i < num_closed; i++) {
if(closed[i]->get_account_number() == accnum)
return closed[i];
}
return 0;
}