so if you were to need to "truncate" the precision of a double, to say 2 decimal places, you might have more than ones way to do it.
The Fast way is (mathy)
double samson = 18945.89374297492742393874;
double shorn = Math.floor(samson * 100) / 100;or you might think, {I'll just format it to a string and parse it back, using the DecimalFormat thingie.
The Slow way is (crufty)
DecimalFormat grading = new DecimalFormat("#.##");
double shorn = Double.parseDouble(grading.format(samson));(on a macbook pro)
mathy takes 10ms to do it 10 million times.
crufty takes 7297ms to it 10 million times.
700% slower.