How to truncate double number with adding missing zeros at the end

Question

Consider I have some double number, I want to truncate it(not round) and leave 4 digits after floating point(exactly 4, always 4, if there are not enough digits - add zeros). Examples:

2344.4234934 -----> 2344.4234
1.345584 -----> 1.3455
34.3434 -------> 34.3434
0.123 ------> 0.1230
1 ---------> 1.0000

I'm using java language, and I'm asking for some built-in functions. I have a solution already but it's too complicated, may be there is an elegant one.

Could you please show your existing solution so we do not suggest that? — David Waters, Jun 10 '15 at 00:23
i used DecimalFormat with floor rounding mode, then I added missing zeros in old-school way + "0" — Petrovskij, Jun 10 '15 at 00:27
What format string did you use with the `DecimalFormat`? That should be all you need to use. You shouldn't need to do anything else with the string once it's returned. — Ian McLaird, Jun 10 '15 at 00:29
possible duplicate of [Are there any functions for truncating a double in java?](http://stackoverflow.com/questions/1976809/are-there-any-functions-for-truncating-a-double-in-java) — David Waters, Jun 10 '15 at 00:30

score 2 · Accepted Answer · answered Jun 10 '15 at 00:39

2

Try this

DecimalFormat fmt = new DecimalFormat("0.0000");
fmt.setRoundingMode(RoundingMode.DOWN);
String s = fmt.format(myDouble);

answered Jun 10 '15 at 00:39

Ian McLaird

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How to truncate double number with adding missing zeros at the end

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