Convert 2 decimal to integer

Question

I want to convert number 2.55 to 255 in java.

I have tried the following code but I am getting 254 instead of 255:

final Double tmp = 2.55;
final Double d = tmp * 100;
final Integer i = d.intValue();

What is the correct way to achieve this?

where does the `2.55` come from? Right now the "correct" solution is to write `i = 255` - depending on where the input actually comes from and in what form the proper answer may vary. — luk2302, Mar 21 '19 at 13:09
https://stackoverflow.com/questions/588004/is-floating-point-math-broken — luk2302, Mar 21 '19 at 13:09
https://stackoverflow.com/questions/322749/retain-precision-with-double-in-java — abj1305, Mar 21 '19 at 13:16

score 3 · Accepted Answer · answered Mar 21 '19 at 13:15

you have to round that value, and you can use primitives for that.. i.e. use the primitive double instead of the wrapper class Double

    final double tmp = 2.55;
    final double d = tmp * 100;
    long i = Math.round(d);

    System.out.println("round: "+ i);

score 2 · Answer 2 · answered Mar 21 '19 at 13:19

It is simple by using BigDecimal

    BigDecimal bg1 = new BigDecimal("123.23");
    BigDecimal bg2 = new BigDecimal("12323");

    bg1= bg1.movePointLeft(-2); // 3 points right

    bg2= bg2.movePointLeft(3);  // 3 points left


    System.out.println(bg1);     //12323

    System.out.println(bg2);     //12.323

Imbar M. · Answer 3 · 2019-03-21T13:24:06.563

1

the value of d is 254.999999999997. this is a problem with floating point calculations. you could use

i = Math.round(d);

to get 255.

--- delete the bottom.. was wrong

edited Mar 21 '19 at 13:24

answered Mar 21 '19 at 13:13

Imbar M.

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Your second proposal does not produce 255 but 2. – georgeliatsos Mar 21 '19 at 13:20

Convert 2 decimal to integer

3 Answers3