Understanding round half even?

Question

When i print

(new BigDecimal(5) * new BigDecimal(0.049))​

It gives

0.24500000000000000943689570931383059360086917877197265625
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Answer 1

int java.math.BigDecimal.ROUND_HALF_EVEN : 6 [0x6]

Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor.

0.24500000000000000943689570931383059360086917877197265625 is closer to 0.25 than to 0.24. The even neighbour is only chosen is the distance from both neighbors is equal (i.e. if you were trying to round 0.245).

BigDecimal bd = new BigDecimal("0.245").setScale(2, BigDecimal.ROUND_HALF_EVEN);
System.out.println (bd);

will print 0.24.