lang/C/the.ansi.c.programming.language/c.programming.notes.int/sx4da.html

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   9 <title>18.1.4: <TT>long double</TT></title>
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  15 <H3>18.1.4: <TT>long double</TT></H3>
  16
  17 <p>The two common floating-point types in C are <TT>float</TT> and <TT>double</TT>.
  18 We haven't said much about the differences between them, because
  19 there isn't much to say:
  20 <TT>double</TT> generally gives you more precision
  21 (more digits' worth of significance),
  22 and perhaps more range
  23 (an ability to use numbers with larger
  24 exponents)
  25 than <TT>float</TT>.
  26 Continuing this progression,
  27 ANSI C added a third floating-point type,
  28 <TT>long double</TT>,
  29 which may give you
  30 even more range
  31 or
  32 even more precision.
  33 If you're using a machine with an extended-precision floating-point format,
  34 <TT>long double</TT> will let you access that format.
  35 But if your machine has only two floating-point formats,
  36 <TT>float</TT> and <TT>double</TT> will probably map to those,
  37 and <TT>long double</TT> won't end up being
  38 any better than plain <TT>double</TT>.
  39 </p><p>The <TT>printf</TT> and <TT>scanf</TT> formats
  40 for <TT>long double</TT>
  41 are <TT>%Le</TT>, <TT>%Lf</TT>, and <TT>%Lg</TT>.
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