gcvt

Remonter à Stdlib.h - Index

Header File

stdlib.h

Category

Conversion Routines, Math Routines

Prototype

char *gcvt(double value, int ndec, char *buf);

Description

Converts floating-point number to a string.

gcvt converts value to a null-terminated ASCII string and stores the string in buf. It produces ndec significant digits in FORTRAN F format, if possible; otherwise, it returns the value in the printf E format (ready for printing). It might suppress trailing zeros.

Return Value

gcvt returns the address of the string pointed to by buf.

Example

 #include <stdlib.h>
 #include <stdio.h>
 int main(void)
 {
    char str[25];
    double num;
    int sig = 5; /* significant digits */
    /* a regular number */
    num = 9.876;
    gcvt(num, sig, str);
    printf("string = %s\n", str);
    /* a negative number */
    num = -123.4567;
    gcvt(num, sig, str);
    printf("string = %s\n", str);
    /* scientific notation */
    num = 0.678e5;
    gcvt(num, sig, str);
    printf("string = %s\n", str);
    return(0);
 }

Portability

POSIX	Win32	ANSI C	ANSI C++
	+