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Redefinition/Indirection Error Message

airowe (29)
I'm getting this error message:

stringManipulation.cpp(178) : error C2372: 's1' : redefinition; different types of indirection


when I try to set a pointer to an array in the following code:

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///////////////////////////////////////////////////////////////////////
//                                                                     
// Filename: stringManipulation.cpp
// 
// 
//
//             
//             
// 
// Description:
//    The string copy function written using pointers.
/////////////////////////////////////////////////////////////////////////#include <iostream>
using namespace std;

//////////////////////////////////////////////////////////////////////
//
// Function: stringCopy                                          
//                                                                   
// Description:
//    Function to copy strings using pointers.                 
//                                                                
// Parameters:  
//    firstParam  : char pointer s1 dereferenced          
//    secondParam : constant char pointer s2 dereferenced               
//                                                       
// Returns:  
//    returnVal : char s1
//                                                                     
///////////////////////////////////////////////////////////////////////	

void stringCopy( char *s1, const char *s2 )
{
     for(int i = 0; *(s1 + i) != '\0'; i++)
		*(s1 + i) = *(s2 + i);
}     

	
//////////////////////////////////////////////////////////////////////
//
// Function: stringCat                                          
//                                                                   
// Description:
//    Concatenation of strings using pointers.                 
//                                                                
// Parameters:  
//    firstParam  : char pointer s1 dereferenced          
//    secondParam : constant char pointer s2 dereferenced               
//                                                       
// Returns:  
//    returnVal : char s1
//                                                                     
///////////////////////////////////////////////////////////////////////

	char *stringCat( char *s1, const char *s2 )
{
    size_t i,j;
    for (i = 0; s1[i] != '\0'; i++)
	{
		for (j = 0; s2[j] != '\0'; j++)
		{
			s1[i+j] = s2[j];
		}
		s1[i+j] = '\0';
		return s1;
	}
}

//////////////////////////////////////////////////////////////////////
//
// Function: strcmpA                                          
//                                                                   
// Description:
//    Comparing strings using array subscripting.                
//                                                                
// Parameters:  
//    firstParam  : constant char pointer s1 dereferenced          
//    secondParam : constant char pointer s2 dereferenced               
//                                                       
// Returns:  
//    returnVal : integer value
//                                                                     
///////////////////////////////////////////////////////////////////////

int strcmpA ( const char *s1, const char * s2 )
{
	for (int i = 0; s1[i] != '\0'; i++)
	{
		if (s1[i] == s2[i])
			return 0;
		else if (s1[i] < s2[i])
			return -1;
		else return 1;
	}
}

//////////////////////////////////////////////////////////////////////
//
// Function: strcmpP                                          
//                                                                   
// Description:
//    Comparing strings using pointer arithmetic.                
//                                                                
// Parameters:  
//    firstParam  : constant char pointer s1 dereferenced          
//    secondParam : constant char pointer s2 dereferenced               
//                                                       
// Returns:  
//    returnVal : integer value
//                                                                     
///////////////////////////////////////////////////////////////////////

int strcmpP ( const char *s1, const char * s2 )
{
	for (int i = 0; *s1 + i != '\0'; i++)
	{
		if (*s1 + i == *s2 + i)
			return 0;
		else if (*s1 + i < *s2 + i)
			return -1;
		else return 1;
	}
}

//////////////////////////////////////////////////////////////////////
//
// Function: strlenA                                          
//                                                                   
// Description:
//    Comparing strings using array subscription.                
//                                                                
// Parameters:  
//    firstParam  : constant char pointer s1 dereferenced                       
//                                                       
// Returns:  
//    returnVal : aCount;
//                                                                     
///////////////////////////////////////////////////////////////////////
int aCount = 0;
size_t strlenA ( const char *s2)
{
	for (int i = 0; s2[i] != '\0'; i++)
		{
			aCount++;
			return aCount;
		}
}

//////////////////////////////////////////////////////////////////////
//
// Function: strlenP                                          
//                                                                   
// Description:
//    Comparing strings using pointer arithmetic.                
//                                                                
// Parameters:  
//    firstParam  : constant char pointer s1 dereferenced                       
//                                                       
// Returns:  
//    returnVal : aCount;
//                                                                     
///////////////////////////////////////////////////////////////////////
int pCount = 0;
size_t strlenP( const char *s2 )
{
	for (int i = 0; *s2 + i != '\0'; i++)
		{
			pCount++;
			return pCount;
		}
}

int main()
{
	char s1[ 100 ] = { 1, 2, 3 };
	char s2[ 100 ] = { 1, 2, 3 };
	char s3[ 100 ] = { 1, 2, 3 };

	char *s1 = s1;
	const char *s2 = s2;
	const char *s3 = s3;	

	stringCopy(*s1, *s2);
	stringCopy(*s1, *s3);

	*stringCat(*s1, *s2);
	*stringCat(*s2, *s3);

	strcmpA(*s2, *s3);
	strcmpA(*s3, *s2);

	strcmpP(*s2, *s3);
	strcmpP(*s3, *s2);

	strlenA(*s1);
	strlenA(*s2);

	strlenP(*s1);
	strlenP(*s2);

	system( "pause" );
	return 0;
}


I get one of these errors every time I set a pointer to point to an array in this problem. I can not figure out why.

Thanks for your help,

Adam
Disch (13742)
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	char s1[ 100 ] = { 1, 2, 3 };
	char s2[ 100 ] = { 1, 2, 3 };
	char s3[ 100 ] = { 1, 2, 3 };

	char *s1 = s1;
	const char *s2 = s2;
	const char *s3 = s3;


You're naming these pointers the same thing as the arrays you defined immediately above them.

The compiler is confused because you have 2 variables in the same scope with the same name, and it has no way to know which variable to use.

rename your arrays.
Last edited on
airowe (29)
Thanks Disch. That cleared up some errors and created some new ones. Now, I'm getting an error message on all of my functions that reads:

.\stringManipulation.cpp(185) : error C2664: 'stringCopy' : cannot convert parameter 1 from 'char' to 'char *'
Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or function-style cast


Here's the updated code:

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///////////////////////////////////////////////////////////////////////
//                                                                     
// Filename: stringManipulation.cpp
// 
//
//
//            
//          
// 
//
// Description:
//    The string copy function written using pointers.
/////////////////////////////////////////////////////////////////////////

#include <iostream>
using namespace std;

	char s1[ 100 ] = { 1, 2, 3 };
	char s2[ 100 ] = { 1, 2, 3 };
	char s3[ 100 ] = { 1, 2, 3 };

	char *s1Ptr = s1;
	const char *s2Ptr = s2;
	const char *s3Ptr = s3;	

//////////////////////////////////////////////////////////////////////
//
// Function: stringCopy                                          
//                                                                   
// Description:
//    Function to copy strings using pointers.                 
//                                                                
// Parameters:  
//    firstParam  : char pointer s1 dereferenced          
//    secondParam : constant char pointer s2 dereferenced               
//                                                       
// Returns:  
//    returnVal : char s1
//                                                                     
///////////////////////////////////////////////////////////////////////	

void stringCopy( char *s1Ptr, const char *s2Ptr )
{
     for(int i = 0; *(s1 + i) != '\0'; i++)
		*(s1 + i) = *(s2 + i);
}     

	
//////////////////////////////////////////////////////////////////////
//
// Function: stringCat                                          
//                                                                   
// Description:
//    Concatenation of strings using pointers.                 
//                                                                
// Parameters:  
//    firstParam  : char pointer s1 dereferenced          
//    secondParam : constant char pointer s2 dereferenced               
//                                                       
// Returns:  
//    returnVal : char s1
//                                                                     
///////////////////////////////////////////////////////////////////////

	char *stringCat( char *s1Ptr, const char *s2Ptr )
{
    size_t i,j;
    for (i = 0; s1[i] != '\0'; i++)
	{
		for (j = 0; s2[j] != '\0'; j++)
		{
			s1[i+j] = s2[j];
		}
		s1[i+j] = '\0';
		return s1;
	}
}

//////////////////////////////////////////////////////////////////////
//
// Function: strcmpA                                          
//                                                                   
// Description:
//    Comparing strings using array subscripting.                
//                                                                
// Parameters:  
//    firstParam  : constant char pointer s1 dereferenced          
//    secondParam : constant char pointer s2 dereferenced               
//                                                       
// Returns:  
//    returnVal : integer value
//                                                                     
///////////////////////////////////////////////////////////////////////

int strcmpA ( const char *s1Ptr, const char *s2Ptr )
{
	for (int i = 0; s1[i] != '\0'; i++)
	{
		if (s1[i] == s2[i])
			return 0;
		else if (s1[i] < s2[i])
			return -1;
		else return 1;
	}
}

//////////////////////////////////////////////////////////////////////
//
// Function: strcmpP                                          
//                                                                   
// Description:
//    Comparing strings using pointer arithmetic.                
//                                                                
// Parameters:  
//    firstParam  : constant char pointer s1 dereferenced          
//    secondParam : constant char pointer s2 dereferenced               
//                                                       
// Returns:  
//    returnVal : integer value
//                                                                     
///////////////////////////////////////////////////////////////////////

int strcmpP ( const char *s1Ptr, const char *s2Ptr )
{
	for (int i = 0; *(s1 + i) != '\0'; i++)
	{
		if (*(s1 + i) == *(s2 + i))
			return 0;
		else if (*(s1 + i) < *(s2 + i))
			return -1;
		else return 1;
	}
}

//////////////////////////////////////////////////////////////////////
//
// Function: strlenA                                          
//                                                                   
// Description:
//    Comparing strings using array subscription.                
//                                                                
// Parameters:  
//    firstParam  : constant char pointer s1 dereferenced                       
//                                                       
// Returns:  
//    returnVal : aCount;
//                                                                     
///////////////////////////////////////////////////////////////////////
int aCount = 0;
size_t strlenA ( const char *s2Ptr)
{
	for (int i = 0; s2[i] != '\0'; i++)
		{
			aCount++;
			return aCount;
		}
}

//////////////////////////////////////////////////////////////////////
//
// Function: strlenP                                          
//                                                                   
// Description:
//    Comparing strings using pointer arithmetic.                
//                                                                
// Parameters:  
//    firstParam  : constant char pointer s1 dereferenced                       
//                                                       
// Returns:  
//    returnVal : aCount;
//                                                                     
///////////////////////////////////////////////////////////////////////
int pCount = 0;
size_t strlenP( const char *s2Ptr )
{
	for (int i = 0; *(s2 + i) != '\0'; i++)
		{
			pCount++;
			return pCount;
		}
}

int main()
{
	stringCopy(*s1Ptr, *s2Ptr);
	stringCopy(*s1Ptr, *s3Ptr);

	*stringCat(*s1Ptr, *s2Ptr);
	*stringCat(*s2Ptr, *s3Ptr);

	strcmpA(*s2Ptr, *s3Ptr);
	strcmpA(*s3Ptr, *s2Ptr);

	strcmpP(*s2Ptr, *s3Ptr);
	strcmpP(*s3Ptr, *s2Ptr);

	strlenA(*s1Ptr);
	strlenA(*s2Ptr);

	strlenP(*s1Ptr);
	strlenP(*s2Ptr);

	system( "pause" );
	return 0;
}


Thanks again for any help!

Adam
LB (13399)
I think on lines 185 to 201 that you're supposed to not be using the deference operator (*) because the functions take pointers to chars (char*) and not chars themselves (char).
airowe (29)
Thanks LB!

Perfect.
Disch (13742)
why did you make everything global? That destroyed all of your functions! Change it back! You shouldn't have any global variables in this program.

EDIT:

Just to reiterate: all of your functions are now broken. None of them are reading/modifying the passed strings, they're all using the globals instead. It effectively makes your functions worthless.
Last edited on
airowe (29)
I changed code. Thanks Disch.
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