See all glossary termsWhen you try to represent 1/3 as a decimal, you can't represent it precisely with a finite number of digits. You need to write
Similarly, computers have a limited number of bits to represent floating-point numbers, so not all real numbers can be represented exactly. Because they use binary, there are different numbers they can't represent well. The decimal value
Because the result is truncated, it does not convert to
This leads to some unexpected results.
For example, in most languages,
Floating point rounding errors are a common problem in computer science; they're not limited to
Floating point numbers can't be compared with
It's also good, when possible, to compare with
Floating Point Rounding Errors
0.3333.... If you wanted to use that calculation in the real world, you would truncate the number, making it less exact.1/3 is difficult to represent in a decimal system.0.1 cannot be represented exactly as a base 2 fraction. In base 2, 1/10 gives us 0.00011001100110011001100110011001...0.1, but to about 0.1000000000000000055511151231257827021181583404541015625.0.1 + 0.1 + 0.1 does not yield 0.3 but something close. In Javascript, you get 0.30000000000000004 (GDScript does correct and give you 0.3 in this case).0.1, that's just an example.How to compare floats?
== or !=, because they're not exact. Instead, we need to use the is_equal_approx() method or is_zero_approx().> and <.