set-output-format.md

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Learn more about: _set_output_format	_set_output_format	11/04/2016	_set_output_format	msvcrt.dll msvcr120.dll msvcr100.dll msvcr110_clr0400.dll msvcr90.dll msvcr110.dll msvcr80.dll	DLLExport	apiref	set_output_format _set_output_format	_TWO_DIGIT_EXPONENT constant output formatting TWO_DIGIT_EXPONENT constant _set_output_format function set_output_format function	1cb48df8-44b4-4400-bd27-287831d6b3ff

_set_output_format

Customizes output formats used by formatted I/O functions.

Important

This function is obsolete. Beginning in Visual Studio 2015, it is not available in the CRT.

Syntax

unsigned int _set_output_format(
   unsigned int format
);

Parameters

format
[in] An value representing the format to use.

Return value

The previous output format.

Remarks

_set_output_format is used to configure the output of formatted I/O functions such as printf_s. The only formatting convention that can be changed by this function is the number of digits displayed in exponents in the output of floating point numbers.

By default, the output of floating point numbers by functions such as printf_s, wprintf_s, and related functions in the Visual C++ Standard C library prints three digits for the exponent, even if three digits aren't required to represent the value of the exponent. Zeroes are used to pad the value to three digits. _set_output_format allows you to change this behavior so that only two digits are printed in the exponent unless a third digit is required by the size of the exponent.

To enable two-digit exponents, call this function with the parameter _TWO_DIGIT_EXPONENT, as shown in the example. To disable two digit exponents, call this function with an argument of 0.

Requirements

Routine	Required header
_set_output_format	<stdio.h>

For more compatibility information, see Compatibility in the Introduction.

Example

// crt_set_output_format.c
#include <stdio.h>

void printvalues(double x, double y)
{
   printf_s("%11.4e %11.4e\n", x, y);
   printf_s("%11.4E %11.4E\n", x, y);
   printf_s("%11.4g %11.4g\n", x, y);
   printf_s("%11.4G %11.4G\n", x, y);
}

int main()
{
   double x = 1.211E-5;
   double y = 2.3056E-112;
   unsigned int old_exponent_format;

   // Use the default format
   printvalues(x, y);

   // Enable two-digit exponent format
   old_exponent_format = _set_output_format(_TWO_DIGIT_EXPONENT);

   printvalues(x, y);

   // Disable two-digit exponent format
   _set_output_format( old_exponent_format );

   printvalues(x, y);
}

1.2110e-005 2.3056e-112
1.2110E-005 2.3056E-112
1.211e-005  2.306e-112
1.211E-005  2.306E-112
1.2110e-05 2.3056e-112
1.2110E-05 2.3056E-112
  1.211e-05  2.306e-112
  1.211E-05  2.306E-112
1.2110e-005 2.3056e-112
1.2110E-005 2.3056E-112
1.211e-005  2.306e-112
1.211E-005  2.306E-112

See also

printf_s, _printf_s_l, wprintf_s, _wprintf_s_l
_get_output_format