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_parnd()
Retrieve a numeric parameter as a double
------------------------------------------------------------------------------
C Prototype
#include "extend.api"
double _parnd(
int iParamNum
[, int iArrayIndex]
)
Arguments
iParamNum is the one-based ordinal position of the parameter in the
parameter list.
iArrayIndex is an array index that specifies a particular element if
the iParamNum parameter is an array.
Returns
_parnd() returns the value of the specified parameter as a double.
Description
_parnd() retrieves a numeric value passed as a parameter from CA-Clipper
and converts it to a double-precision floating point value.
_parnd() returns a far pointer to a statically allocated buffer that
contains the double numeric value. When you call _parnd() from C, the
double value is automatically copied from the buffer into your C
variable. If you call from Assembly language, however, you should take
care to preserve the double value since subsequent calls to _parnd()
will overwrite the buffer.
Examples
. From C:
double num;
num = _parnd(1);
. From Assembly language:
EXTRN __parnd:FAR
mov ax, 1
push ax
call __parnd ; value pointed to by DX:AX
add sp, 2 ; reset stack pointer
mov es, dx ; load pointer in ES:BX
mov bx, ax ; copy double into save area
; (creation of save area not shown)
;
mov word ptr MySaveArea, es:[bx]
mov word ptr MySaveArea+2, es:[bx+2]
mov word ptr MySaveArea+4, es:[bx+4]
mov word PTR MySaveArea+6, es:[bx+6]
Files Library is CLIPPER.LIB, header file is Extend.api.
See Also:
_parni()
_parnl()
_retnd()
_stornd()
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