[c] C: convert double to float, preserving decimal point precision

i wanted to convert double to float in C, but wanted to preserve the decimal point exactly as possible without any changes...

for example, let's say i have

   double d = 0.1108;
   double dd = 639728.170000;
   double ddd = 345.2345678

now correct me if i am wrong, i know that floating point precision is about 5 numbers after the dot. can i get those five numbers after the dot exactly as the double had it? so that above results as follows:

   float f = x(d);
   float ff = x(dd);
   float fff = x(ddd);

   printf("%f\n%f\n%f\n", f, ff, fff);

it should print

   0.1108
   639728.17000
   345.23456

all digits after the precision limit (which i assume as 5) would be truncated.

A float generally has about 7 digits of precision, regardless of the position of the decimal point. So if you want 5 digits of precision after the decimal, you'll need to limit the range of the numbers to less than somewhere around +/-100.

Floating point numbers are represented in scientific notation as a number of only seven significant digits multiplied by a larger number that represents the place of the decimal place. More information about it on Wikipedia:

http://en.wikipedia.org/wiki/Floating_point