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Q29557: printf() Default Floating-Point Precision Is 6 Decimals

Article: Q29557
Product(s): Microsoft C Compiler
Version(s): winnt:
Operating System(s): 
Keyword(s): kbCRT kbVC
Last Modified: 22-JUL-2001

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The information in this article applies to:

- The C Run-Time (CRT), included with:
   - Microsoft C for MS-DOS, versions 5.0, 5.1, 6.0, 6.0a, 6.0ax 
   - Microsoft C for OS/2, versions 5.1, 6.0, 6.0a 
   - Microsoft C/C++ for MS-DOS, version 7.0 
   - Microsoft Visual C++, versions 1.0, 1.50 
   - *EDITOR Please do not choose this product*Microsoft Visual C++ 32-bit Edition* use 241, 265, 225, versions 1.0, 2.0, 4.0 
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SUMMARY
=======


By default, the printf() function displays a floating-point number to six digits
of precision. This default also holds for double precision numbers.

To display additional digits of precision, specify a value for the precision
field in the printf() format specification, as follows:

  %[<flags>][<width>][.<precision>]<type>

MORE INFORMATION
================

The code example below demonstrates documented printf() behavior that may appear
to be a problem with the function.

     #include <stdio.h>

     main()
     {
        double d = 1.2345678912;

        printf("%e\n", d);
        printf("%le\n", d);
     }

This code example produces the following output:

  1.234568e+000
  1.234568e+000

To display the value d to its full precision, modify the code example to use the
following statement:

     printf("%.15le", d);

Additional query words: kbinf 1.00 1.50 2.00 5.10 6.00 6.00a 6.00ax 7.00

======================================================================
Keywords          : kbCRT kbVC 
Technology        : kbVCsearch kbAudDeveloper kbCRT
Version           : winnt:

=============================================================================

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