How do I round to the nearest ten?

Question

How can I round a number to the nearest ten with no if statements? For example, 98 to 100.

int num = 87;
double t;
double d = 1.0 * num; // d = 87.0
t = d/100;
System.out.println(t);

Duplicate/similar: https://stackoverflow.com/questions/9303604/rounding-up-a-number-to-nearest-multiple-of-5 — Mr-IDE, Sep 04 '18 at 18:43

Zarwan · Answer 1 · 2016-10-03T07:09:15.857

35

You can use Math.round(num/10.0) * 10.

edited Oct 03 '16 at 07:09

answered Oct 03 '16 at 05:15

Zarwan

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if you divide by 10d or 10.0, num can be any (primitive) number. – Peter Walser Oct 03 '16 at 07:08
True, edited. @Peter – Zarwan Oct 03 '16 at 07:09

score 23 · Answer 2 · edited May 23 '17 at 10:31

23

answer = ((num+5)/10)*10; // if num is int

where num is int and to have more idea, read this quesiton. How to round a number to n decimal places in Java.
Edit:
if num is double add typecasting to expression (long)((num+5)/10) as suggested by @PeterLawrey

edited May 23 '17 at 10:31

Community

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answered Oct 03 '16 at 05:16

sinsuren

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Are you sure? If `num` is 14.0 then this will evaluate to 20. – Bathsheba Oct 03 '16 at 07:09
I might be having a senior moment but the last time I checked, (14.0 + 5) / 10 is 1.9 which becomes 2.0 on rounding. Remember that `Math.round` implements German rounding. – Bathsheba Oct 03 '16 at 07:11
The cast of an int to an int is redundant, worse if it's already a long. – Peter Lawrey Oct 03 '16 at 07:58
@sinsuren the cast is needed if it's a double but then you would use long if possible. It's an int for the OP's question. – Peter Lawrey Oct 03 '16 at 08:18
@PeterLawrey I have changed according to your suggestion. Thankyou for improving answer quality. – sinsuren Oct 03 '16 at 08:31
Thanks @sinsuren it worked. Also thanks everyone who helped – Cmi Oct 03 '16 at 14:27

How do I round to the nearest ten?

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