Rounding double to int always to the smaller

Question

I want to convert double values to int values in java. I am encountering the problem that simple casting doesn't work as I want and the Math.round() doesn't do it either.

My goal is that the doubles should be rounded down to the next smaller int. As following:

 0.5 ->  0
 1.7 ->  1
 2.9 ->  2
-0.3 -> -1
-3.9 -> -4

The problem mostly are the different handling methods smaller than 0. Since I don't want them to round to the higher, but to the lower value.

Is there a java-native function for this, or how can I implement this effectively? I thought of the following, but I'd rather use a java-native function.

double d = -0.1D; // or whatever else
int i = (double) ((int) d) <= d ? (int) d : (int) d - 1;

Answer 1

Use

double d = ...
int n = (int)Math.floor(d);