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Once the item has been stored in datanode it can be
retrieved by first interrogating the TAG field. See King P.
345-350 or K&R P. 148
What now if you wanted an array of such a variant record
structure?
(As indeed you might for the second assignment!)
typedef struct node* Nodeptr;
typedefstruct node {
int TAG;
union {
int digits;
float number;
} data;
} Node;
At this stage we have only a definition of a sample element
in our array. If we wanted to create M of them we would
first need to declare a pointer to such an element
Nodeptr np;
then get space for the array with
np = (Nodeptr) malloc (M*sizeof(Node));
or
np = (Nodeptr) calloc (M, sizeof(Node));
To access the zero'th TAG field we could write
kind = np->TAG;
while the i'th tag:
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