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   9 <title>15.2: Accessing Members of Structures</title>
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  15 <H2>15.2: Accessing Members of Structures</H2>
  16
  17 <p>We said that a structure was a little bit like an array:
  18 a collection of members (elements).
  19 We access the elements of an array
  20 by using a numeric subscript in square brackets <TT>[]</TT>.
  21 We access the elements of a structure
  22 by name,
  23 using the
  24 <dfn>structure selection operator</dfn> which is a dot (a period).
  25 The structure selection operator is a little like
  26 the other binary operators we've seen,
  27 but much more restricted:
  28 on its left must be a variable or object of structure type,
  29 and on its right must be the name of one of the members of that structure.
  30 For example,
  31 if <TT>c1</TT> is a variable of type <TT>struct complex</TT>
  32 as declared in the previous section,
  33 then <TT>c1.real</TT> is its real part
  34 and <TT>c1.imag</TT> is its imaginary part.
  35 </p><p>Like subscripted array references,
  36 references to the members of structure variables
  37 (using the structure selection operator)
  38 can appear anywhere,
  39 either on the right or left side of assignment operators.
  40 We could say
  41 <pre>
  42         c1.real = 1
  43 </pre>
  44 to set the real part of <TT>c1</TT>
  45 (that is, the <TT>real</TT> member within <TT>c1</TT>)
  46 to 1,
  47 or
  48 <pre>
  49         c1.imag = c2.imag
  50 </pre>
  51 to fetch the imaginary part of <TT>c2</TT> and assign it to
  52 the imaginary part of <TT>c1</TT>,
  53 or
  54 <pre>
  55         c1.real = c2.real + c3.real
  56 </pre>
  57 to take the real parts of <TT>c2</TT> and <TT>c3</TT>,
  58 add them together,
  59 and assign the result to the real part of <TT>c1</TT>.
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