should help you out Given that you state your question has no practical application, I figure you're trying to learn about floating point number representations.

Thus, if you're looking for a solution without using any library support, start with the

format specification. From that you can discern the various "special" values (Infinity, NAN, etc) as well as decoding/calculating the actual numeric value. Once you have the significand and exponent, you know where to put the decimal point. You'll have to write your own

itoa type routine. For radices which are a power of two, this can be as simple as a lookup table. For decimal, you'll have to do a little extra math.

code :