Constants and Variables with macro : const « Data Type « C Tutorial

1. C Tutorial
2. Data Type
3. const

#include <stdio.h>
 
#define SPEED 55
 
int main()
{
      printf("SPEED %i.\n",SPEED);
      printf("SPEED+15 %i.\n",SPEED+15);
      printf(" %i MPH sign?\n",SPEED);
      return(0);
}

SPEED 55.
      SPEED+15 70.
       55 MPH sign?