|
ActiveTcl User Guide |
|
Tcl_PrintDouble - Convert floating value to string
#include <tcl.h>
Tcl_PrintDouble(interp, value, dst)
- Tcl_Interp *interp
(in)
- Before Tcl 8.0, the tcl_precision variable in this
interpreter controlled the conversion. As of Tcl 8.0, this argument
is ignored and the conversion is controlled by the
tcl_precision variable that is now shared by all
interpreters.
- double value (in)
- Floating-point value to be converted.
- char *dst (out)
- Where to store the string representing value. Must have
at least TCL_DOUBLE_SPACE characters of storage.
Tcl_PrintDouble generates a string that represents the value
of value and stores it in memory at the location given by
dst. It uses %g format to generate the string, with
one special twist: the string is guaranteed to contain either a
“.” or an “e” so that it does not look like
an integer. Where %g would generate an integer with no
decimal point, Tcl_PrintDouble adds “.0”.
If the tcl_precision value is non-zero, the result will
have precisely that many digits of significance. If the value is
zero (the default), the result will have the fewest digits needed
to represent the number in such a way that Tcl_NewDoubleObj will generate
the same number when presented with the given string. IEEE
semantics of rounding to even apply to the conversion.
conversion, double-precision, floating-point, string
Copyright © 1995-1997 Roger E. Critchlow Jr.
Copyright © 1989-1993 The Regents of the University of
California. Copyright © 1994-1997 Sun Microsystems, Inc.