0.1 in binary, is a repeating decimal - just like how 1/3 in base 10 is a repeating decimal.
So you get errors due to rounding.
This is also why it's super important in loops to never use "=" as a condition statement, but instead use "<=" (or ">="). Otherwise you might create an infinite loop.
Never seems a bit strong, it depends on the context. You can use = on int types all day.
I'm not sure what you mean; those aren't integers (if that's what you mean by "whole number float"):
python3
>>> 0.4 == 0.6 - 0.2
False
(edit: formatting for python)
Or something like this?
But if you are storing the weight of a product a float might be fine - you don't really care if the system thinks you have 50.000001 pounds of product when you have 50 pounds (because your scale isn't that accurate anyway).
Floats will generally give you better performance than decimal types as well.
decimal n = 123.456m;Also, a plain integer is usually sufficient for financial calculations (just count pennies, not dollars) so in some ways I think decimal types are overused when an integer would do just fine.