Keep up to 3 decimals without doing any rounding

Question

I have a double that I want to keep only 3 decimal places but without applying any rounding at all.
E.g. 92.36699 should be 92.366
I tried the following:

DecimalFormat nf= new DecimalFormat("#0.000");  
String number = nf.format(originalNumber);

But this results in 92.367
How can I do what I need?

You could use integer-division: `((originalNumber * 1000) / 1) / 1000.0` — IQV, Feb 02 '17 at 10:30

Boris the Spider · Accepted Answer · 2017-02-02T10:32:55.107

4

This isn't "no rounding", it's DOWN rounding. Simply set the roundingMode.

DecimalFormat nf = new DecimalFormat("#0.000");  
nf.setRoundingMode(RoundingMode.DOWN);
String number = nf.format(originalNumber);

Note the difference between FLOOR and DOWN - only relevant for negative numbers. FLOOR rounds towards negative infinity therefore -92.36699 would become "-92.367".

edited Feb 02 '17 at 10:32

answered Feb 02 '17 at 10:31

Boris the Spider

59,842
6
106
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Truncation is properly done with `RoundingMode.DOWN` as `RoudingMode.FLOOR` always rounds towards negative infinity. – Papershine Feb 02 '17 at 10:32
@paper1111 just adding a note on that. Fair point on which one to use by default. – Boris the Spider Feb 02 '17 at 10:33

Keep up to 3 decimals without doing any rounding

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