Rounding negative numbers in Java

Question

According to Wikipedia when rounding a negative number, you round the absolute number. So by that reasoning, -3.5 would be rounded to -4. But when I use java.lang.Math.round

Answer 1

The Wikipedia article you cite does not say that's the only way to round, just the common way to round. Also mentioned in that article are several alternatives (unfortunately none of which describe Java's rounding method - even though they call it out as "Asymmetric Arithmetic Rounding" when indicating what JavaScript does).

You need to decide how you want your numbers rounded, then use that method. If Java's implementation matches that, then great. otherwise you'll need to implement it on your own.