%i, %d, %f ??

I was just playing around with Win32 MessageBox and sprintf... when i noticed that when i try to put a double into an array of chars with sprintf it messes up when i use %d or %i, but it works for ints.

here is what i mean

Code:

int x = 1280;
int y = 1024;
double r = static_cast<double>(x)/static_cast<double>(y);
char szBuffer[100];
sprintf(szBuffer, "X: %i, Y: %i, R: %i", x, y, r);
OUTPUT:
X: 1280, Y: 1024, R: 0

sprintf(szBuffer, "X: %d, Y: %d, R: %d", x, y, r);
OUTPUT:
X: 1280, Y: 1024, R: 0

sprintf(szBuffer, "X: %d, Y: %d, R: %d", x, y, r);
OUTPUT:
X: 1280, Y: 1024, R: 1.250000

i tried variations with all the letters in the alphabet and i got weird things like CCCCCCD or cccccd.

Can anyone tell me what the %i is for and how its used and the %d and %f and any other ones if there are.

Thanks

http://si.php.net/sprintf
It's for PHP, but I think there isn't much difference between PHP's sprintf() and sprintf() in C++

FAQ > How do I... (Level 1) > Format output using printf() (C)

The short answer to the original question is that %d and %i work for int types, but %f is for double types. Keep in mind that the ONLY information that the internals of functions like printf() receive about the type of arguments is what you provide in the format string. If you call

Code:

printf("%d\n", a_double);

the internals of printf() receives no information that a_double is a double rather than an int.