Re: Using numbers as float
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- Subject: Re: Using numbers as float
- From: Mark Edgar <medgar@...>
- Date: 2006年6月29日 12:41:14 -0700
Jose Marin wrote:
Hi.
I'm compiling Lua to use floats, altering the file
luser_number.h .
The macro lua_str2number uses strtod (returns a
double).
I could cast to (float)strtod, but I'm worried abou
performance.
Is there some fast way of convert a string to a float?
Thanks!
strtod() works just fine; no cast is required:
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
float x = strtod("3.2", NULL);
printf("%f\n", x);
return 0;
}
You probably won't find anything faster, as your implementation's
strtod() is probably written in nice fast assembly.
If you have a C99 conforming system, you can use strtof() instead. I
don't know that you'll notice a performance difference between strtod()
and strtof().
-Mark