strings (dollar.cents) into floats

[Robert Kern]

Wildemar Wildenburger wrote:
> Ben Finney wrote:
>> You most likely do *not* want floating-point numbers for currency,
>> since they rely on the operating system's binary floating point
>> support which cannot accurately represent decimal fractions.
> 
> I've heard (ok, read) that several times now and I understand the 
> argument. But what use is there for floats, then? When is it OK to use them?

There are many, many situations where one is *not* trying to represent numbers
that have nice decimal fractions or the error induced is insignificant to the
problem. For example, I might take temperature readings good to 0.1 degrees
Celcius. I'll type those numbers in decimal even though when I do my
calculations I'll use floating point math because the error (about 1e-15 or so)
is so far below the error in my measurement (about 0.1) that I won't have problems.

Binary floating point has the advantage of being widely implemented and quite
fast compared to decimal floating point.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco