How do I pass the & instead of a ptr?

[Profetas]

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
void reverse(char *str);

int main(void)
{
char *string;

printf( "Enter a line of text:\n" );
scanf("%s", &string);

printf( "The string printed backwards is: " );
reverse(&string);
puts("\0");
exit(EXIT_SUCCESS);
}

void reverse(char *str)
{
if( str[0]=='\0')
{
return;
}
else
{
reverse(&str[1]);
putchar(str[0]);
}
}

 

[pete]

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
void reverse(char *str);

int main(void)
{
char *string;

printf( "Enter a line of text:\n" );
scanf("%s", &string);

printf( "The string printed backwards is: " );
reverse(&string);
reverse(string);

puts("\0");
exit(EXIT_SUCCESS);
}

void reverse(char *str)
{
if( str[0]=='\0')
{
return;
}
else
{

The following isn't going to work without major revision.

reverse(&str[1]);
putchar(str[0]);
}
}

 

[S.Tobias]

In addition, you don't allocate space for string.

int main(void)
{
char *string;

char string[100];

printf( "Enter a line of text:\n" );
scanf("%s", &string);

scanf("%s", string);

 

[Dave]

void reverse(char *str)
{
if( str[0]=='\0')
{
return;
}
else
{

The following isn't going to work without major revision.

Um, no, it's fine (if a slightly cack-handed way of doing it, using
tail-recursion instead of a simple iteration - your confusion indicating
perfectly why it's cack-handed).

reverse(&str[1]);
putchar(str[0]);
}
}

 

[Kelsey Bjarnason]

[snips]

reverse(string);

Funny that you pointed this out, but not the fact that the scanf is hooped
- twice. Once by the fact it's using &, and again by the fact there's no
space reserved for the string.

 

[Barry Schwarz]

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
void reverse(char *str);

int main(void)
{
char *string;

printf( "Enter a line of text:\n" );
scanf("%s", &string);

This will cause scanf to store the data it reads into string itself,
not into any area string might point to. I'm pretty sure this is not
what you intended.

printf( "The string printed backwards is: " );
reverse(&string);

Your prototype says reverse takes a char*. &string is a char**. Your
compiler should produce a diagnostic for this.

puts("\0");
exit(EXIT_SUCCESS);
}

void reverse(char *str)
{
if( str[0]=='\0')

Learn to indent consistently. It will save you a lot of aggravation
later.

{
return;
}
else

The else is superfluous.

{
reverse(&str[1]);
putchar(str[0]);
}
}

Your question makes no sense and many readers will not even see it.
Include a cogent statement of what problem you need help with in the
body of your message.


<<Remove the del for email>>

 

[pete]

void reverse(char *str)
{
if( str[0]=='\0')
{
return;
}
else
{

The following isn't going to work without major revision.

Um, no, it's fine (if a slightly cack-handed way of doing it, using
tail-recursion instead of a simple iteration
- your confusion indicating
perfectly why it's cack-handed).

Thank you.

 

[Tim Rentsch]

void reverse(char *str)
{
if( str[0]=='\0')
{
return;
}
else
{

The following isn't going to work without major revision.

Um, no, it's fine (if a slightly cack-handed way of doing it, using
tail-recursion instead of a simple iteration - your confusion indicating
perfectly why it's cack-handed).

reverse(&str[1]);
putchar(str[0]);
}
}

Recursion, yes. But not tail recursion. There is a 'putchar()' after
the call to 'reverse()'.

 

[pete]

[snips]

reverse(string);

Funny that you pointed this out,
but not the fact that the scanf is hooped
- twice. Once by the fact it's using &,
and again by the fact there's no space reserved for the string.

OK. Stop laughing.