Question

I have a

   map<Float,Object>.

I need it store valuse like

0.01 ->ObjA
0.02 ->ObjB

and sometimes

0.001 ->ObjA
0.002 ->ObjB (three digits after the dot)

I thought it would be easy.
But I have notice that when I calculate simple calculation with the float
I sometimes get stuff like this.

0.09998
0.02001 —– instead of (0.01, 0.02)

I know that float isnt that good for that usage so I have tried double and clearly I got a map filled with
0.0999999998
0.0200000001
naturally.

So I think I should round it. but it is not that easy since I dont know to which size.

sometimes it should be 0.03 and sometimes 0.3.
Thanks for your assistance.

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EDIT: Thanks for all the answers. I think my problem is that I get 5.00001 instead of 5 . not that I enter 5.000001 to a map. I would like to round the float and each time to the best value I can find . and since it is alwas 0.0000000X or 0.999999X I think It should be easy. But I haven’t figured it out yet.

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Answer 1

Try using

Map<BigDecimal, Object> 

BigDecimal will allow you to define floating point values exactly.