Thread: Can you check what is wrong with this code

Header file

Code:

#ifndef STRING_HPP
#define STRING_HPP

#include <iostream>

using namespace std;

/* mystring class */
class mystring
{
    public:

    typedef struct STRING* String;

     /*String struct */
    struct STRING
    {
        int size;
        char *theString;
    };




void validateString( mystring& theString );

mystring()
{
	String->theString = NULL;
	String->size =0;
}
mystring( const char *init)
{
	newString( init );
}

~mystring(mystring& theString)
{
	destroyString( theString );
}
mystring&  destroyString( mystring& theString );
mystring& newString( char* theString );
char* charAt(  mystring& theString, int index );
void printString( mystring& theString);
friend mystring& operator+(  mystring& string1,  mystring& string2 );

};



#endif

Function file

Code:

#include <iostream.h>

#include <assert.h>
#include "mystring.hpp"
using namespace std;

int stringCount = 0; /*Keep track of string count */
/*------------------------------------------------------
 newString

 PURPOSE: Create a new string struct
 INPUT PARAMETERS:input string
 OUTPUT PARAMETERS: string object
------------------------------------------------------ */

mystring& mystring::newString( const char* init )
{
  String *newString = NULL;

  assert( init != NULL );

  newString = new String[init];
  assert( newString != NULL );

  if ( newString != NULL )
  {
    newString->theString = new char( strlen(init) + 1 ); /*Assign array size of the new string object*/
    assert( newString -> theString != NULL );

    if ( newString -> theString != NULL )
    {
      strcpy( newString -> theString, init );/*Copy input string to string component of the struct */
      newString -> size = strlen( newString -> theString );/*Assign size of the String object */

      assert( newString -> size == strlen( init ) );

      stringCount++;
    }

    else
    {
      delete newString ;
      newString = NULL;
    }
  }

  return( newString );
}

/*------------------------------------------------------
 validateString

 PURPOSE: To check if there is any content in the object or empty object */
 INPUT PARAMETERS:string object
 OUTPUT PARAMETERS: void
------------------------------------------------------ */

 void mystring::validateString(  mystring& theString )
{
  assert( theString != NULL );
  assert( theString -> theString != NULL );
  assert( theString -> theString[theString -> size] == '\0' );
}

/*------------------------------------------------------
 destroyString

 PURPOSE: Destroys the string struct
 INPUT PARAMETERS:string object
 OUTPUT PARAMETERS: string object
------------------------------------------------------ */

mystring& mystring::destroyString( mystring& theString )
{
  validateString( theString );
  assert( stringCount > 0 );

  delete theString -> theString ; /*Delete String component of the struct */
  delete theString ; /*Delete the object itself */
  theString = NULL;

  stringCount--;

  return( theString );
}


char* mystring::charAt(  mystring& theString, int index )
{
  validateString( theString );
  assert( index >= 0 );
  assert( index < theString -> size );

  return( theString -> theString[index] );
}

/*------------------------------------------------------
 operator+
 PURPOSE: Operator overloading of the operator +
 INPUT PARAMETERS:string object
 OUTPUT PARAMETERS: new string object which has contents of string1 and 2
------------------------------------------------------ */

mystring& mystring::operator+(   mystring& string1, mystring& string2 )
{
  String *newString = NULL;

  validateString( string2 );

  newString = new String[];
  assert( newString != NULL );

  if ( newString != NULL )
  {
    newString -> size = this. size + string2 -> size;
    newString -> theString = new char [newString -> size + 1];
    assert( newString -> theString != NULL );

    if ( newString -> theString != NULL )
    {
      strcpy( newString -> theString, string1 -> theString );
      strcpy( &(newString -> theString[string1 -> size]), string2 -> theString );

      assert( newString -> size == strlen( newString -> theString ) );
      assert( newString -> theString[0] == this. theString[0] );
      assert( newString -> theString[this. size] == string2 -> theString[0] );

      stringCount++;
    }

    else
    {
      delete newString ;
      newString = NULL;
    }
  }

  return( newString );
}

/*------------------------------------------------------
 printString

 PURPOSE: Print the contents of the string object
 INPUT PARAMETERS: string onject
 OUTPUT PARAMETERS: void
------------------------------------------------------ */

void mystring::printString(  mystring& theString )
{
  validateString( theString );

  cout << theString->size<<endl;
  cout << theString -> theString << endl ;
}