c - Pointers for a beginner (with code) -

i doing first ever homework assignment in c , i'm trying grasp pointers. make sense in theory, in execution i'm little fuzzy. have code, supposed take integer x, find least significant byte, , replace y byte in same location. gcc returns with:

"2.59.c:34:2: warning: passing argument 1 of ‘replace_with_lowest_byte_in_x’ makes pointer integer without cast [enabled default]

2.59.c:15:6: note: expected ‘byte_pointer’ argument of type ‘int’"

and same argument 2. kind explain me going on here?

#include <stdio.h>   typedef unsigned char *byte_pointer;   void show_bytes(byte_pointer start, int length) {     int i;     (i=0; < length; i++) {         printf(" %.2x", start[i]);     }     printf("\n"); }  void replace_with_lowest_byte_in_x(byte_pointer x, byte_pointer y) {     int length = sizeof(int);     show_bytes(x, length);     show_bytes(y, length);     int i;     int lowest;     lowest = x[0];     (i=0; < length; i++) {         if (x[i] < x[lowest]) {             lowest = i;         }     }     y[lowest] = x[lowest];     show_bytes(y, length); }  int main(void) {       replace_with_lowest_byte_in_x(12345,54321);      return 0; } 

the function expects 2 pointers you're passing integer(-constant)s. want put numbers in own variables , pass addresses of function: (in main):

int = 12345, b = 54321;  replace_with_lowest_byte_in_x(&a, &b); 

note you're still passing incompatible pointers.