* vs &

Applications Programming
1

what's the difference between *(pointer) and &(reference)? sometime i see code use * and sometime it uses &, i'm comfuse as when to use which.
thanks.

2

They are the reverse of each other. The ampersand gives you an address of an object. The star uses an address stored in an object.

int i, *p;
i=5;   /* i is now 5 */
p=&i;  /* the address of i is now stored in p */
*p=6;  /* i is now 6 but p did not change */
3

& is also used in "pass by reference" in C++ (not C). Works like pointers but some people may consider easier to work with by reference instead of pointers:

#include <stdio.h>
void add(int &a, int b) {
   // adds a and b, and put result to
   // variable referenced by "a"
   a += b;
}
int main(int argc, char** argv) {
   int myval = 4;
   // myval references to "a" in add(), so a change
   // to either one modifies the same variable
   add(myval, 6);
   printf("%d\n", myval);    // should be 10
   return 0;
}
4

just a few pointers.. (;))

Unlike pointers, you must immediately initialize a reference:

Also remember that you can't use an operator to operate on the reference like you can do with pointers. An example...