rounding off in java

[Vasim Patel]

Hi

How do I round off the decimal in java to the nearest .05
e.g:
1.499 should 1.5.
But 1.49 should still be 1.49.

[Mani Ram]

Check java.text.DecimalFormat

[Vasim Patel]

Hi Mani

Thanks a lot. I am not too clear how to achieve what I want. DecimalFormat is more for formatting the decimal numbers.
I am interested in rounding off.
Can you please give an example using the API

[Mani Ram]

There is a method called setMaximumFractionDigits() in that class.
That might be useful.

[David Harkness]

 

Originally posted by Vasim Patel:
How do I round off the decimal in java to the nearest .05

Since 0.05 is a decimal number, and float/double are binary approximations of decimal numbers, you can't be guaranteed to round exactly using them. If you just want to get close, try this:

double value = 0.499;
double rounding = 0.05;
double rounded = Math.rint(value / rounding) * rounding;

In words, you shift the rounding scale to be 1 instead of 0.05, round the value to nearest integer, and shift back. If you need exact decimal values, use java.math.BigDecimal.