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   9 <title>Chapter 2: Types, Operators, and Expressions</title>
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  15 <H1>Chapter 2: Types, Operators, and Expressions</H1>
  16
  17 <p>page 35
  18 </p><p>Deep sentence:
  19 <blockquote>The type of an object determines the set of values it can have
  20 and what operations can be performed on it.
  21 </blockquote>This is a fairly formal, mathematical definition of what a type is,
  22 but it is traditional (and meaningful).
  23 There are several implications to remember:
  24 </p><OL><li>The ``set of values'' is
  25 finite.
  26 C's <TT>int</TT> type can not represent <em>all</em> of the integers;
  27 its <TT>float</TT> type can not represent <em>all</em>
  28 floating-point numbers.
  29 <li>When you're using an object (that is, a variable) of some type,
  30 you
  31 may
  32 have to remember what values it can take on and what
  33 operations you can perform on it.
  34 For example,
  35 there are several operators which
  36 play with
  37
  38 the binary (bit-level) representation of integers,
  39 but these operators
  40 are not meaningful for
  41 and may not be applied to
  42 floating-point operands.
  43 <li>When declaring a new variable and picking a type for it,
  44 you have to keep in mind the values and operations you'll be needing.
  45 </OL>In other words,
  46 picking a type for a variable is not some abstract academic exercise;
  47 it's closely
  48 connected
  49 to the way(s) you'll be using that variable.
  50 <p>You don't need to worry about
  51 the
  52 list of ``small changes and additions'' made by the ANSI standard,
  53 unless you started learning C long ago or have a keen interest
  54 in its history.
  55 We'll be using these new features indiscriminately,
  56 usually without comment.
  57
  58 </p><p><a href="sx5a.html" rel=subdocument>section 2.1: Variable Names</a></p>
  59 <p><a href="sx5b.html" rel=subdocument>section 2.2: Data Types and Sizes</a></p>
  60 <p><a href="sx5c.html" rel=subdocument>section 2.3: Constants</a></p>
  61 <p><a href="sx5d.html" rel=subdocument>section 2.4: Declarations</a></p>
  62 <p><a href="sx5e.html" rel=subdocument>section 2.5: Arithmetic Operators</a></p>
  63 <p><a href="sx5f.html" rel=subdocument>section 2.6: Relational and Logical Operators</a></p>
  64 <p><a href="sx5g.html" rel=subdocument>section 2.7: Type Conversions</a></p>
  65 <p><a href="sx5h.html" rel=subdocument>section 2.8: Increment and Decrement Operators</a></p>
  66 <p><a href="sx5i.html" rel=subdocument>section 2.9: Bitwise Operators</a></p>
  67 <p><a href="sx5j.html" rel=subdocument>section 2.10: Assignment Operators and Expressions</a></p>
  68 <p><a href="sx5k.html" rel=subdocument>section 2.11: Conditional Expressions</a></p>
  69 <p><a href="sx5l.html" rel=subdocument>section 2.12: Precedence and Order of Evaluation</a></p>
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  79 This page by <a href="http://www.eskimo.com/~scs/">Steve Summit</a>
  80 // <a href="copyright.html">Copyright</a> 1995, 1996
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