Delete a key from an Associative Array
assoc_delete_key (Assoc_Type a, String_Type k)
The assoc_delete_key function deletes a key given by k
from the associative array a.  If the specified key does not
exist in a, then this function has no effect.
Return all the key names of an Associative Array
String_Type[] assoc_get_keys (Assoc_Type a)
This function returns all the key names of an associative array
a as an ordinary one dimensional array of strings.  If the
associative array contains no keys, an empty array will be returned.
assoc_get_values, assoc_key_exists, assoc_delete_key, length
Return all the values of an Associative Array
Array_Type assoc_get_keys (Assoc_Type a)
This function returns all the values in the associative array
a as an array of proper type.  If the associative array
contains no keys, an empty array will be returned.
Suppose that a is an associative array of type
Integer_Type, i.e., it was created via
      variable a = Assoc_Type[Integer_Type];
Then the following may be used to print the values of the array in
ascending order:
      define print_sorted_values (a)
      {
         variable v = assoc_get_values (a);
         variable i = array_sort (v);
         v = v[i];
         foreach (v)
           {
              variable vi = ();
              () = fprintf (stdout, "%d\n", vi);
           }
      }
assoc_get_keys, assoc_key_exists, assoc_delete_key, array_sort
Check to see whether a key exists in an Associative Array
Integer_Type assoc_key_exists (Assoc_Type a, String_Type k)
The assoc_key_exists function may be used to determine whether
or not a specified key k exists in an associative array a.
It returns 1 if the key exists, or 0 if it does not.