Thread: need help with pointers

the first function works (int length (char a[]), but the output to the second function is -28865. I need to use pointers and pointer arithmatic.

Code:

#include <stdio.h>
#include <string.h>

int length (char a[]);
int point_size (int *a);

int main()
{
char word[]="Trying this out";
int size;
int pointer_eh;

size = length (word);

printf("The length is %d\n", size);

printf("The length is %d", pointer_eh);


return 0;
}


int length (char a[])
{
	int i;
	int size=0;

        clrscr();

        for (i = 0; i != strlen(a); i++)
	{
		size++;
	}
	return(size);
}

int point_size (int *a)
{

	int i, pointer_eh;

	while (*a[i] != '\0')
	{
		*(a+1);
	 	i++;
	}
	return (pointer_eh);
}

if you need to use pointer math, you can eliminate all your little "++" operations that you're doing on an integer. You need to do those on a pointer instead. Additionally, use a forward slash not a back slash to end your code tags
edit: you got it already!

point_eh in main is never given a value, so what you're doing is printing whatever happens to be at that memory location when the program is run. I assume that point_size is the pointer notation equivalent of length, so this would be what you want:

Code:

#include <stdio.h>
#include <string.h>

int length (char a[]);
int point_size (char *a);

int main()
{
        char word[]="Trying this out";
        int size;
        int pointer_eh;

        size = length (word);
        pointer_eh = point_size (word);

        printf("The length is %d\n", size);
        printf("The length is %d\n", pointer_eh);

        return 0;
}


int length (char a[])
{
        int i;
        int size=0;

        /*clrscr();*/

        for (i = 0; i != strlen(a); i++)
        {
                size++;
        }
        return(size);
}

int point_size (char *a)
{

        int i = 0, pointer_eh;

        while (*(a+i) != '\0')
        {
                *(a+1);
                i++;
        }
        return (pointer_eh);
}

if a is a pointer to a char, then *(a+1) is a "dereferenced" pointer to the next char in memory. So it is the char that follows *a. Get it?

Code:

int point_size (char *a)
{

        int i = 0, pointer_eh;

        while (*(a+i) != '\0')
        {
                *(a+1);
                i++;
        }
        return (pointer_eh);
}

what value has pointer_eh?
Undeclared, because you dont assign it any value.