将2十进制转换为整数

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?

Answer 1

you have to round that value, and you can use primitives for that.. ie 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);

Answer 2

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

Answer 3

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