c++ - 指针问题

Question

有人知道如何在多维数组中存储指针吗？我认为这可能是我在 main 中遇到的问题:

// main.cpp
#ifdef  _DEBUG
#define _CRTDBG_MAP_ALLOC
#include <iostream>
#include <fstream>
#include <string>
#endif
#include "Word.h"
using namespace std;

const int WORD_SZ = 100;
Word** g_wordArray;
int g_arrSz;

static char filePath[ FILE_PATH_SZ ] = {};
void FreeWordArray();

int main( const int argc, const char **argv )
{
    int 
        wrdCount = 0;
    char 
        usrMenuOption     = 0,
        getFirstLetter    = 0,
        tmpArray[WORD_SZ] = {},
        *getWord = new char;
    string 
        str, 
        str2;
    ifstream 
        inFile, 
        inFile2;
    do 
    {
        cout << "Please make a selection: \n\
a) Read a text file\n\
b) Remove words starting with letter\n\
c) Print words to console\n\
d) Quit\n";
        cin  >> usrMenuOption;
        switch( usrMenuOption )
        {
        case'A':
        case'a':
            cout << "Enter a file name: ";
            cin.sync();
            cin  >> filePath;
            inFile.open( filePath );
            if ( !inFile ) return -1;
            inFile >> tmpArray; // prime the eof flag.
            while ( !inFile.eof() )
            {   
                inFile >> tmpArray;
                wrdCount++;
                g_wordArray = new Word *[wrdCount];

            }
        inFile.close();
        inFile2.open( filePath );
        while( !inFile2.eof()  )
        {   
            inFile2 >> tmpArray;
            // supplies the member functions with information from the file
            g_wordArray[wrdCount] = new Word( tmpArray );
            g_wordArray[wrdCount]->GetFirstLetterLower();
            g_wordArray[wrdCount]->GetWord();
        }
        cout << wrdCount << " Words read from the file " << endl;
        inFile2.close();
        break;
        case'B':
        case'b':
        // information not found returning null
                g_wordArray[wrdCount]->GetFirstLetterLower();
        break;
        case'C':
        case'c':
                g_wordArray[wrdCount]->GetWord();
        break;
        case'D':
        case'd':
        cout << "Quit Requested. " << endl;
        break;
        default:
        cout << '"' << usrMenuOption << '"' << " Not Defined! " << endl;
        }

    } while ( usrMenuOption != 'D' && usrMenuOption != 'd' );


#ifdef _DEBUG
    _CrtDumpMemoryLeaks();
#endif
    cin.ignore();
    return 0;
}

void FreeWordArray()
{
    delete[ ] g_wordArray;
    return;
}


// Word.cpp
#define _CRT_SECURE_NO_WARNINGS // disable warnings for strcpy
#define ARRY_SZ 100
#include <iostream>
#include <fstream>
#include "Word.h"
#include <vector>


using namespace std;

// No paramaters.
// Is this what im missing?
// I just threw it in because of an error.
Word::Word() 
{
}

Word::Word( const char* word )
{
    ptr_ = new char[ strlen( word ) + 1 ];
    strcpy( ptr_, word  ); 
    len_ = strlen( ptr_ );
}

Word::~Word()
{
    delete[ ] ptr_;
    ptr_ = NULL;
    len_ = NULL;
}

char Word::GetFirstLetterLower()
{
    char myChar = tolower( ptr_[0] );
    return myChar;

}

char* Word::GetWord()
{
    Word *objectOne = new Word;
    objectOne->ptr_ = ptr_;
    strcpy( objectOne->ptr_, ptr_ );
    return objectOne->ptr_;
}

我的目标是在我的 g_wordArray[wrdCount]->SomeFunction() 中从文件中读取所有单词，而不依赖于文件读取循环。

我一直在努力做的事情:

• 在实现文件中，在getFirstLetterLower 下:每次将char *_ptr 私有(private)成员添加到一个新变量中。像 someCharVar[0] = firstWord, someCharVar[1] = secondWord...

• 将文件内容读入单个变量。在我需要的每种情况下循环遍历该变量。

我喜欢这个想法，但还不知道如何去做。有什么建议吗？

Answer 1

请发布可以重现您的问题的最少代码。现在看起来很朦胧。我想这段代码有很多问题

        inFile >> tmpArray;     // prime the eof flag.
        while ( !inFile.eof() )
        {       
                inFile >> tmpArray;
                wrdCount++;
                g_wordArray = new Word *[wrdCount];

        }

你在这里严重泄漏内存。先前分配的“g_wordArray”会怎样？

此外，当您分配“n”个元素时，您无法访问“第 n 个”索引。内存占用范围为 0 - (n-1)。

g_wordArray[wrdCount]

请重新检查代码，尝试调试，然后发布最少的代码。