Programming in C

Working with Pointers and Structures 245

Figure 11.3 Structure containing pointers.

This defines a structure called entry, which contains two members.The first member of
the structure is a simple integer called value.The second member of the structure is a
member called next, which is a pointer to an entrystructure.Think about this for a
moment. Contained inside an entrystructure is a pointer to another entrystructure.
This is a perfectly valid concept in the C language. Now suppose you define two vari-
ables to be of type struct entryas follows:

struct entry n1, n2;

You set the next pointer of structure n1to point to structure n2by executing the fol-
lowing statement:

n1.next = &n2;

This statement effectively makes a link between n1and n2, as depicted in Figure 11.4.

pointers

p1

p2

100

-97

i1

i2

n1

value

next

n2

value

next

Figure 11.4 Linked structures.