_fcvt

Converts a floating-point number to a string.

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

For additional compatibility information, see Compatibility in the Introduction.

Libraries

Return Value

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

Parameters

value

Number to be converted

count

Number of digits after decimal point

dec

   Pointer to stored decimal-point position

sign

  Pointer to stored sign indicator

Remarks

The _fcvt function converts a floating-point number to a null-terminated character string. The value parameter is the floating-point number to be converted. _fcvt stores the digits of value as a string and appends a null character ('\0'). The count parameter specifies the number of digits to be stored after the decimal point. Excess digits are rounded off to count places. If there are fewer than count digits of precision, 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; this integer value gives the position of the decimal point with respect to the beginning of the string. A zero or negative integer value indicates that the decimal point lies to the left of the first digit. The parameter sign points to an integer indicating the sign of value. The integer is set to 0 if value is positive and is set to a nonzero number if value is negative.

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

Example

/* FCVT.C: This program converts the constant
 * 3.1415926535 to a string and sets the pointer
 * *buffer to point to that string.
 */

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

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

   buffer = _fcvt( source, 7, &decimal, &sign );
   printf( "source: %2.10f   buffer: '%s'   decimal: %d   sign: %d\n",
            source, buffer, decimal, sign );
}

Output

source: 3.1415926535   buffer: '31415927'   decimal: 1   sign: 0
 

Data Conversion Routines |  Floating-Point Support Routines

See Also   atof, _ecvt, _gcvt