Round a double in Java

Question

I have found this great solution for rounding:

static Double round(Double d, int precise) {
    BigDecimal bigDecimal = new BigDecimal(d);
    bigDecimal = b         


        

Answer 1

Rounding a double resp Double in itself does not make much sense, as a double datatype cannot be rounded (easily, or at all?).

What you are doing is:

1. Take a Double d as input and a int precise number of digits behind the seperator.
2. Create a BigDecimal from that d.
3. Round the BigDecimal correctly.
4. Return the double value of that BigDecimal, which has no rounding applied to it anymore.

You can go two ways:

1. You can return a BigDecimal that represents the rounded double, and later decide what you do with it.
2. You can return a String representing the rounded BigDecimal.

Either of those ways will make sense.