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   9 <title>section 2.2: Data Types and Sizes</title>
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  15 <H2>section 2.2: Data Types and Sizes</H2>
  16
  17 page 36
  18 <p>If you can look at this list of
  19 ``a few basic types in C''
  20 and say to yourself,
  21 ``Oh, how simple, there are only a few types,
  22 I won't have to worry much about choosing among them,''
  23 you'll have an easy time with declarations.
  24 (Some masochists wish that the type system were more complicated
  25 so that you could specify more things about each variable,
  26 but those of us who would rather not have to specify these
  27 extra things each time are glad that we don't have to.)
  28 </p><p>Note that the basic types are defined as having
  29 <em>at least</em> a certain size.
  30 There is no specification that
  31 a <TT>short int</TT> will be exactly 16 bits,
  32 or that a <TT>long int</TT> will be exactly 32 bits.
  33 Some programmers become obsessed with knowing exactly what
  34 sizes things will be in various situations,
  35 and write programs which depend on things having certain sizes.
  36 Exact sizes are occasionally important,
  37 but most of the time we can sidestep size issues
  38 and let the compiler do most of the worrying.
  39 </p><p>Most of the simple variables in most programs are of types
  40 <TT>int</TT>, <TT>long int</TT>, or <TT>double</TT>.
  41 Typically, we'll use <TT>int</TT> and <TT>double</TT> for most
  42 purposes, and <TT>long int</TT> any time we need to hold values
  43 greater than 32,767.
  44 We'll rarely use individual variables of type <TT>char</TT>;
  45 although we'll use plenty of arrays of <TT>char</TT>.
  46 Types <TT>short int</TT> and <TT>float</TT> are important primarily when
  47 efficiency (speed or memory usage) is a concern,
  48 and for us it usually won't be.
  49 </p><p>Note that even when we're manipulating individual characters,
  50 we'll usually use an <TT>int</TT> variable,
  51 for the reason discussed in section 1.5.1
  52 on page 16.
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  62 This page by <a href="http://www.eskimo.com/~scs/">Steve Summit</a>
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