Quote Originally Posted by dee-u View Post
How can I convert a number like 1.21932631356501E+215 to its complete form?
That's not really a floating point number; that's a very large integer. My solutions are very different for both problems.

For storing the exact value of a decimal, I would store the numerator and denominator. So instead of a floating point .333..., I'd store the integers 1 and 3. This of course won't work for irrational numbers, but those can't be stored with exact precision pretty much by definition. (Right?)

To handle very large integers, however, I'd set up my own math processor. This has come up in the past, and Logophobic has pointed out that using strings for this is hugely inefficient. But it works well for pointing you in the right direction.

Store those two numbers as strings. Then set up loops to go through and do your addition / subtraction / whatever exactly the same way you were taught in elementary school. For addition, add the two right-most digits together, carry the 1, move left one and add the next set of digits, carry the 1, etc...

EDIT: Come to think of it, Logo may have actually posted a functional solution. I'm too lazy to search for it now, though.