Using an enumeration type : enum « Data Type « C Tutorial

1. C Tutorial
2. Data Type
3. enum

#include <stdio.h>

enum months { 
   JAN = 1, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC };

int main()
{ 
   enum months month; 

   const char *monthName[] = { "", "January", "February", "March", 
      "April", "May", "June", "July", "August", "September", "October",
      "November", "December" };
   
   for ( month = JAN; month <= DEC; month++ ) {
      printf( "%2d%11s\n", month, monthName[ month ] );
   } 

   return 0;
}

1    January
 2   February
 3      March
 4      April
 5        May
 6       June
 7       July
 8     August
 9  September
10    October
11   November
12   December