Thread: Pointer Help

Your assignment is wrong.

a = b;

This puts the value of b into a, not the other way around. See what you have:

Code:

if ( *pval1 > *pval2 )
		store = *pval1;
	else 
		store = *pval2;

Your assignment is backwards.

*pval1 = store;

This will make the value of whatever 'pval1' points at hold whatever is currently in the value 'store'. Otherwise what happens is that you put the value of 'pval1'-contents into 'store'. Since 'store' is a local variable, it is destroyed when the function ends.

Quzah.

I'm not sure I understood you, but:

Code:

#include <stdio.h>

void int_sort(int*,int*);

int main()
{
	int val1, *pval1, val2, *pval2;

	printf( "Enter two numbers: " );
	scanf( "%d %d", &val1, &val2);

	pval1 = &val1;
	pval2 = &val2;

	int_sort(pval1,pval2);

	printf("The smaller: %d, and the bigger: %d\n",val2,val1);
	return 0;
}

void int_sort( int *pval1, int *pval2 )
{
	int tmp;
	
	//this will put the max value in val2 and the smaller in val2
	if (*pval1 < *pval2) {
		tmp = *pval1;
		*pval1 = *pval2;
		*pval2 = tmp;
	}
}

And you don't need pval1 and pval2 here, this could be like this too:

Code:

#include <stdio.h>

void int_sort(int*,int*);

int main()
{
	int val1,val2;
	printf( "Enter two numbers: " );
	scanf( "%d %d", &val1, &val2);

	int_sort(&val1,&val2);

	printf("The smaller: %d, and the bigger: %d\n",val2,val1);
	return 0;
}

void int_sort( int *pval1, int *pval2 )
{
	int tmp;
	
	//this will put the max value in val2 and the smaller in val2
	if (*pval1 < *pval2) {
		tmp = *pval1;
		*pval1 = *pval2;
		*pval2 = tmp;
	}
}

But maybe you want something special, I don't know.
Ahh and you need somechanges to see if they're equal

Originally posted by cman
yep i know it works but its not what i want it to do.
i want to store one value in one pointer and another value in another pointer, compare the two values, and then return the larger value first then the smaller one second.

the program here just returns the higher value. sorry for the bad explanation.

You can't return more than one value, so maybe you mean you want to swap the numbers around if one is bigger than the other.

Does this help you:

Code:

#include <stdio.h>

void changer(int *i1, int *i2)
{
  int temp;
  if (*i1 > *i2)
  {
    temp = *i1;
    *i1 = *i2;
    *i2 = temp;
  }
}

int main(void)
{
  int i, j;
  
  i = 1;
  j = 3;
  changer(&i, &j);
  printf ("Passing 1,3 gets %d, %d\n", i, j);
  
  i = 3;
  j = 1;
  changer(&i, &j);
  printf ("Passing 3,1 gets %d, %d\n", i, j);
  
  return 0;
}