Using the C Preprocessor for easy iterating

main.c

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

//A Preprocessor Macro for iterating
#define FOR_EACH(array, type, block) { \
  int len = sizeof(array)/sizeof(type);\
  for(int i=0; i<len; i++){            \
      type this = array[i];            \
      block                            \
  }                                    \
}                                      \

int main(int argc, char *argv[]){
  //Example 1: Iterate through a list of strings 
  char* array1[] = {"one","two", "three"};

  FOR_EACH(array1, char* , {
    fprintf(stdout, "ITERATE = %s\n", this);
  });

  fprintf(stdout, "\n\n");

  //Example 2: Iterate through a list of ints 
  int array2[] = {0,1,2,3,4,5,6,7,8,9};

  FOR_EACH(array2, int, {
    int doubled = this + this;
    fprintf(stdout, "Doubled Int = %d\n", doubled);
  });
}