Visual Studio 6.0

Converts a double number to a string.

char *_ecvt( double value, int count, int *dec, int *sign );

Function Required Header Compatibility
_ecvt <stdlib.h> Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.


LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version

Return Value

_ecvt returns a pointer to the string of digits. There is no error return.



Number to be converted


Number of digits stored


Stored decimal-point position


Sign of converted number


The _ecvt function converts a floating-point number to a character string. The value parameter is the floating-point number to be converted. This function stores up to count digits of value as a string and appends a null character ('\0'). If the number of digits in value exceeds count, the low-order digit is rounded. If there are fewer than count digits, the string is padded with zeros.

Only digits are stored in the string. The position of the decimal point and the sign of value can be obtained from dec and sign after the call. The dec parameter points to an integer value giving the position of the decimal point with respect to the beginning of the string. A 0 or negative integer value indicates that the decimal point lies to the left of the first digit. The sign parameter points to an integer that indicates the sign of the converted number. If the integer value is 0, the number is positive. Otherwise, the number is negative.

_ecvt and _fcvt use a single statically allocated buffer for the conversion. Each call to one of these routines destroys the result of the previous call.


/* ECVT.C: This program uses _ecvt to convert a
 * floating-point number to a character string.

#include <stdlib.h>
#include <stdio.h>

void main( void )
   int     decimal,   sign;
   char    *buffer;
   int     precision = 10;
   double  source = 3.1415926535;

   buffer = _ecvt( source, precision, &decimal, &sign );
   printf( "source: %2.10f   buffer: '%s'  decimal: %d  sign: %d\n",
           source, buffer, decimal, sign );


source: 3.1415926535   buffer: '3141592654'  decimal: 1   sign: 0

Data Conversion RoutinesFloating-Point Support Routines

See Also   atof, _fcvt, _gcvt