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strcmp

The following error appears: 'strcmp' : cannot convert parameter 1
from 'char' to 'const char *'. I've already tried using single
quotations. the header file
only contains the struct contents. The whole program is part of an
example found in my course work. Does strcmp only compare two sets of
strings or can it be used to determine the end of the string as well?

#include<iostream>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include "program2v.h"

using namespace std;

int main()
{
crecord *string1, *string2, t_str;

*string1 = t_str;

/// the error while( strcmp(*string1->customername, "\0"))
{
*string2 = *string1 + 1;
while( strcmp(*string2->customername, '\0'))
{
if(strcmp( *string1->customername, *string2->customername) > 0 )
{
t_str = *string1;
*string1 = *string2;
*string2 = t_str;

}
string2++;
}
string1++;
}
return 0;
}
Jul 19 '05 #1
6 12295
"muser" <ch**********@hotmail.com> wrote in message
news:f9**************************@posting.google.c om...
The following error appears: 'strcmp' : cannot convert parameter 1
from 'char' to 'const char *'. I've already tried using single
quotations. the header file
only contains the struct contents. The whole program is part of an
example found in my course work. Does strcmp only compare two sets of
strings or can it be used to determine the end of the string as well?

#include<iostream>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include "program2v.h"

using namespace std;

int main()
{
crecord *string1, *string2, t_str;

*string1 = t_str;
Uhm, 'string1' is a wild pointer, and you are just mighty lucky you did
not blow up your program right here. Make sure 'string1' and 'string2' point
to valid objects before working with them.

/// the error while( strcmp(*string1->customername, "\0"))
{
*string2 = *string1 + 1;
Same here. You are dereferencing pointer with an unknown value ...
while( strcmp(*string2->customername, '\0'))
What are you trying to do? 'strcmp', as the name suggests, takes two
strings (ie. char-arrays) and compares them. It looks like you want to
compare plain chars? If so, do this:

while (*string2->customername != '\0')
{
if(strcmp( *string1->customername, *string2->customername) > 0 )
What is the type of crecord::customername? char* ?
{
t_str = *string1;
*string1 = *string2;
*string2 = t_str;

}
string2++;
}
string1++;
}
return 0;
}


No offense, but I suggest you get a good tutorial online or a book
before coding more. From that snippet above, you seem to be confused by
pointers and objects and string manipulation.

hth
--
jb

(replace y with x if you want to reply by e-mail)
Jul 19 '05 #2
"muser" <ch**********@hotmail.com> wrote in message
news:f9**************************@posting.google.c om...
/// the error while( strcmp(*string1->customername, "\0"))
{
*string2 = *string1 + 1;
while( strcmp(*string2->customername, '\0'))
{
if(strcmp( *string1->customername, *string2->customername) > 0 )
{


Where is your structure defined ? Specifically, I need to know what data
type the "customername" field is. Also, the '\0' argument is not a valid
parameter type to strcmp(). What are you trying to accomplish ? If
customername is a pointer to a character string and you want to test if the
string is empty, you can just do something like:

while (*(string2->customername) == '\0')

Jul 19 '05 #3
muser wrote:

The following error appears: 'strcmp' : cannot convert parameter 1
from 'char' to 'const char *'. I've already tried using single
quotations. the header file
only contains the struct contents. The whole program is part of an
example found in my course work. Does strcmp only compare two sets of
strings or can it be used to determine the end of the string as well?

#include<iostream>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include "program2v.h"

using namespace std;

int main()
{
crecord *string1, *string2, t_str;
What is crecord?
*string1 = t_str;
You deferenced a pointer without having set it to any value. Where do
you think string1 points?

/// the error while( strcmp(*string1->customername, "\0"))


What is customername? What type? Are you sure that dereference does what
you think it does?
In the future, post *complete* minimal programs. We don't have your
header file.

Also, explain what the basic concept of the program is. Your code had no
comments at all.


Brian Rodenborn
Jul 19 '05 #4
Default User <fi********@company.com> wrote in message news:<3F***************@company.com>...
muser wrote:

The following error appears: 'strcmp' : cannot convert parameter 1
from 'char' to 'const char *'. I've already tried using single
quotations. the header file
only contains the struct contents. The whole program is part of an
example found in my course work. Does strcmp only compare two sets of
strings or can it be used to determine the end of the string as well?

#include<iostream>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include "program2v.h"

using namespace std;

int main()
{
crecord *string1, *string2, t_str;


What is crecord?
*string1 = t_str;


You deferenced a pointer without having set it to any value. Where do
you think string1 points?

/// the error while( strcmp(*string1->customername, "\0"))


What is customername? What type? Are you sure that dereference does what
you think it does?
In the future, post *complete* minimal programs. We don't have your
header file.

Also, explain what the basic concept of the program is. Your code had no
comments at all.


Brian Rodenborn

my code again in a simpler reworked format. strcmp produces the
following error:
C:\Program Files\Microsoft Visual
Studio\MyProjects\Valid\program2\program2v.cpp(52) : error C2664:
'strcmp' : cannot convert parameter 1 from 'char' to 'const char *'

if string1 and string 2 have to be const chars, how can i dereference
them later in the function?
#include <iostream>
#include <iomanip>
#include <fstream>
#include <cstring>
#include <cstdlib>
using namespace std;

struct crecord {
long customercode[5];
char customername[21];
char customeraddress[61];
double customerbalance;
double creditlimit;
};
crecord Newcrecord;

struct irrecord {
long customercode[5];
long partnum[5];
long issue_rec;

};
irrecord Newirrecord;

struct drecord {
long customercode[5];
};
drecord Newdrecord;

void sort( char* record )
{
char t_str;
char characterstring[5];
char* string1;
char* string2;
strncpy(characterstring, &record[2], 5);
characterstring[5] = '\0';

while(*(string1) != '\0')
{
*string2 = *string1;
*string2++;

while( *(string2) != '\0')
{
if(strcmp( *string1, *string2 ) > 0)
{
t_str = *string1;
*string1 = *string2;
*string2 = t_str;

}
string2++;
}
string1++;
}
return;
}




int main()
{
const char outfile[] = "A:\\514650VD.DAT";
ofstream validdata;

char temp2[256];

return 0;

}
Jul 19 '05 #5
muser wrote:
my code again in a simpler reworked format. strcmp produces the
following error:
C:\Program Files\Microsoft Visual
Studio\MyProjects\Valid\program2\program2v.cpp(52) : error C2664:
'strcmp' : cannot convert parameter 1 from 'char' to 'const char *'

if string1 and string 2 have to be const chars, how can i dereference
them later in the function?
The have to be POINTERS to const char. You are passing in a single char.
char* string1;
char* string2; if(strcmp( *string1, *string2 ) > 0)

You dereference the two char pointers, which yields a char, which
generates a diagnostic. Hurray, the system works! Go with this:

if(strcmp( string1, string2 ) > 0)

Brian Rodenborn
Jul 19 '05 #6
ch**********@hotmail.com (muser) writes:
The following error appears: 'strcmp' : cannot convert parameter 1
from 'char' to 'const char *'. I've already tried using single
quotations. the header file
only contains the struct contents.
... which would be necessary to understand what's going on here.
Please post the minimal *complete*, *compilable* example showing your
problem.
The whole program is part of an
example found in my course work. Does strcmp only compare two sets of
strings or can it be used to determine the end of the string as well?

#include<iostream>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include "program2v.h"

using namespace std;

int main()
{
crecord *string1, *string2, t_str;

*string1 = t_str;
Here you're assigning to a pointer for which no memory has been allocated.
/// the error while( strcmp(*string1->customername, "\0"))


It seems that crecord::customername is a char - strcmp is for comparing
char*. If you really want to compare two chars (which I doubt),
just use operator==, e.g.

if (*string1->customername == '\0')

Note the single quote.
I'm also wondering what you want to achieve with dereferencing
string1->customername - but without the header file, it's impossible to guess.

HTH & kind regards
frank

--
Frank Schmitt
4SC AG phone: +49 89 700763-0
e-mail: frankNO DOT SPAMschmitt AT 4sc DOT com
Jul 19 '05 #7

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