Bad pointer? - C ++

Question

I am writing a string tokenization program for setting homework in C ++ that uses pointers. However, when I run and debug it, it says that my pStart pointer is invalid. I feel that my problem is with my param'ed constructor, I included both the constructor and the creation of the object below.

I would appreciate it if you could tell me why it says pStart is a bad pointer when I debug it.

Thank!

StringTokenizer::StringTokenizer(char* pArray, char d)
{
pStart = pArray;
delim = d;
}

// create a tokenizer object, pass in the char array
// and a space character for the delimiter
StringTokenizer tk( "A test char array", ' ' );

Full stringtokenizer.cpp file:

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

StringTokenizer::StringTokenizer(void)
{
pStart = NULL;
delim = 'n';
}

StringTokenizer::StringTokenizer(const char* pArray, char d)
{
pStart = pArray;
delim = d;
}

char* StringTokenizer::Next(void)
{
char* pNextWord = NULL;

while (pStart != NULL)
{
    if (*pStart == delim)
    {
        *pStart = '\0';
        pStart++;
        pNextWord = pStart;

        return pNextWord;
    }
    else
    {
        pStart++;
    }
}
    return pNextWord;
}

The Next supossed function returns a pointer to the next word in the char array. It is not completed at present. :)

Full stringtokenizer.h:

#pragma once

class StringTokenizer
{
public:
StringTokenizer(void);
StringTokenizer(const char*, char);
char* Next(void);
~StringTokenizer(void);
private:
char* pStart;
char delim;
};

Full main.cpp file:

const int CHAR_ARRAY_CAPACITY = 128;
const int CHAR_ARRAY_CAPCITY_MINUS_ONE = 127;

// create a place to hold the user input
// and a char pointer to use with the next( ) function
char words[CHAR_ARRAY_CAPACITY];
char* nextWord;

cout << "\nString Tokenizer Project";
cout << "\nyour name\n\n";
cout << "Enter in a short string of words:";
cin.getline ( words, CHAR_ARRAY_CAPCITY_MINUS_ONE );

// create a tokenizer object, pass in the char array
// and a space character for the delimiter
StringTokenizer tk( words, ' ' );

// this loop will display the tokens
while ( ( nextWord = tk.Next ( ) ) != NULL )
{
    cout << nextWord << endl;
}


system("PAUSE");
return 0;

Answer 1

pStart StringTokenizer char * const char * .

Answer 2

pStart , C ++ , const char *.

pStart = pArray;

, pStart . , . , .

: , , . . , :

while (pStart != NULL)

:

while (pStart != NULL && *pStart)

, , '\0' .

, C- ++. ?

Answer 3

StringTokenizer::StringTokenizer(char* pArray, char d)

StringTokenizer::StringTokenizer(const char * pArray, char d)

const char * const, ++ non const const, const const.

, , , pArray.

- :

TokenList& StringTokenizer::StringTokenizer(const char* pArray, char d){
  TokenList lst();
  size_t i=0;
  char buffer[100]; //hardcoded limit, just an example, you should make it grow dinamically, or just use a std::string
  while((*pArray)){
    if(*pArray == d){
      buffer[i] = 0; //string ending character, 0 = '\0';
      lst.add(buffer);
      i=0;
    }
    pArray++;
  }
  //Last token in the input string won't be ended by the separator, but with a '\0'.
  buffer[i] = 0;
  lst.add(buffer);

  return lst;
}

Answer 4

-, StringTokenizer:

StringTokenizer::StringTokenizer(char* pArray, char d)
{
    pStart = str = strdup( pArray );
    delim = d;
}

StringTokenizer::~StringTokenizer(char* pArray, char d)
{
    free( str );
}

pStart , : , .. "char * str" StringTokenizer.

, , , , , . , ( ).

, , , , const char *, "" .